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Human cannibalism

Human cannibalism is the act or practice of humans eating the flesh or internal organs of other human beings. A person who practices cannibalism is called a cannibal. The meaning of "cannibalism" has been extended into zoology to describe animals consuming parts of individuals of the same species as food.

Anatomically modern humans, Neanderthals, and Homo antecessor are known to have practised cannibalism to some extent in the Pleistocene. Cannibalism was occasionally practised in Egypt during ancient and Roman times, as well as later during severe famines. The Island Caribs of the Lesser Antilles, whose name is the origin of the word cannibal, acquired a long-standing reputation as eaters of human flesh, reconfirmed when their legends were recorded in the 17th century. Some controversy exists over the accuracy of these legends and the prevalence of actual cannibalism in the culture.

Cannibalism has been well documented in much of the world, including Fiji (once nicknamed the "Cannibal Isles"), the Amazon Basin, the Congo, and the Māori people of New Zealand. Cannibalism was also practised in New Guinea and in parts of the Solomon Islands, and human flesh was sold at markets in some parts of Melanesia and of the Congo Basin. A form of cannibalism popular in early modern Europe was the consumption of body parts or blood for medical purposes. Reaching its height during the 17th century, this practice continued in some cases into the second half of the 19th century.

Cannibalism has occasionally been practised as a last resort by people suffering from famine. Well-known examples include the ill-fated Donner Party (1846–1847), the Holodomor (1932–1933), and the crash of Uruguayan Air Force Flight 571 (1972), after which the survivors ate the bodies of the dead. Additionally, there are cases of people engaging in cannibalism for sexual pleasure, such as Albert Fish, Issei Sagawa, Jeffrey Dahmer, and Armin Meiwes. Cannibalism has been both practised and fiercely condemned in several recent wars, especially in Liberia and the Democratic Republic of the Congo. It was still practised in Papua New Guinea as of 2012, for cultural reasons.

Cannibalism has been said to test the bounds of cultural relativism because it challenges anthropologists "to define what is or is not beyond the pale of acceptable human behavior". A few scholars argue that no firm evidence exists that cannibalism has ever been a socially acceptable practice anywhere in the world, but such views have been largely rejected as irreconcilable with the actual evidence.

Etymology
The word "cannibal" is derived from Spanish caníbal or caríbal, originally used as a name variant for the Kalinago (Island Caribs), a people from the West Indies said to have eaten human flesh. The older term anthropophagy, meaning "eating humans", is also used for human cannibalism.

Reasons and types
Cannibalism has been practised under a variety of circumstances and for various motives. To adequately express this diversity, Shirley Lindenbaum suggests that "it might be better to talk about 'cannibalisms in the plural.

Institutionalized, survival, and pathological cannibalism
One major distinction is whether cannibal acts are accepted by the culture in which they occur – institutionalized cannibalism – or whether they are merely practised under starvation conditions to ensure one's immediate survival – survival cannibalism – or by isolated individuals considered criminal and often pathological by society at large – cannibalism as psychopathology or "aberrant behavior". Institutionalized cannibalism, sometimes also called "learned cannibalism", is the consumption of human body parts as "an institutionalized practice" generally accepted in the culture where it occurs. By contrast, survival cannibalism means "the consumption of others under conditions of starvation such as shipwreck, military siege, and famine, in which persons normally averse to the idea are driven [to it] by the will to live". Also known as famine cannibalism, such forms of cannibalism resorted to only in situations of extreme necessity have occurred in many cultures where cannibalism is otherwise clearly rejected. The survivors of the shipwrecks of the Essex and Méduse in the 19th century are said to have engaged in cannibalism, as did the members of Franklin's lost expedition and the Donner Party.

Such cases often involve only necro-cannibalism (eating the corpse of someone already dead) as opposed to homicidal cannibalism (killing someone for food). In modern English law, the latter is always considered a crime, even in the most trying circumstances. The case of R v Dudley and Stephens, in which two men were found guilty of murder for killing and eating a cabin boy while adrift at sea in a lifeboat, set the precedent that necessity is no defence to a charge of murder. This decision outlawed and effectively ended the practice of shipwrecked sailors drawing lots in order to determine who would be killed and eaten to prevent the others from starving, a time-honoured practice formerly known as a "custom of the sea".

In other cases, cannibalism is an expression of a psychopathology or mental disorder, condemned by the society in which it occurs and "considered to be an indicator of [a] severe personality disorder or psychosis". Well-known cases include Albert Fish, Issei Sagawa, and Armin Meiwes. Fantasies of cannibalism, whether acted out or not, are not specifically mentioned in manuals of mental disorders such as the DSM, presumably because at least serious cases (that lead to murder) are very rare.

Exo-, endo-, and autocannibalism
Within institutionalized cannibalism, exocannibalism is often distinguished from endocannibalism. Endocannibalism refers to the consumption of a person from the same community. Often it is a part of a funerary ceremony, similar to burial or cremation in other cultures. The consumption of the recently deceased in such rites can be considered "an act of affection" and a major part of the grieving process. It has also been explained as a way of guiding the souls of the dead into the bodies of living descendants.

In contrast, exocannibalism is the consumption of a person from outside the community. It is frequently "an act of aggression, often in the context of warfare", where the flesh of killed or captured enemies may be eaten to celebrate one's victory over them.

Some scholars explain both types of cannibalism as due to a belief that eating a person's flesh or internal organs will endow the cannibal with some of the positive characteristics of the deceased. However, several authors investigating exocannibalism in New Zealand, New Guinea, and the Congo Basin observe that such beliefs were absent in these regions.

A further type, different from both exo- and endocannibalism, is autocannibalism (also called autophagy or self-cannibalism), "the act of eating parts of oneself". It does not ever seem to have been an institutionalized practice, but occasionally occurs as pathological behaviour, or due to other reasons such as curiosity. Also on record are instances of forced autocannibalism committed as acts of aggression, where individuals are forced to eat parts of their own bodies as a form of torture.

Additional motives
Exocannibalism is thus often associated with the consumption of enemies as an act of aggression, a practice also known as war cannibalism. Endocannibalism is often associated with the consumption of deceased relatives in funerary rites driven by affection – a practice known as funerary or mortuary cannibalism. But acts of institutionalized cannibalism can also be driven by various other motives, for which additional names have been coined.''

Medicinal cannibalism (also called medical cannibalism) means "the ingestion of human tissue ... as a supposed medicine or tonic". In contrast to other forms of cannibalism, which Europeans generally frowned upon, the "medicinal ingestion" of various "human body parts was widely practiced throughout Europe from the sixteenth to the eighteenth centuries", with early records of the practice going back to the first century CE. It was also frequently practised in China.

Sacrificial cannibalism refers the consumption of the flesh of victims of human sacrifice, for example among the Aztecs. Human and animal remains excavated in Knossos, Crete, have been interpreted as evidence of a ritual in which children and sheep were sacrificed and eaten together during the Bronze Age. According to Ancient Roman reports, the Celts in Britain practised sacrificial cannibalism, and archaeological evidence backing these claims has by now been found.

Infanticidal cannibalism or cannibalistic infanticide refers to cases where newborns or infants are killed because they are "considered unwanted or unfit to live" and then "consumed by the mother, father, both parents or close relatives". Infanticide followed by cannibalism was practised in various regions, but is particularly well documented among Aboriginal Australians. Among animals, such behaviour is called filial cannibalism, and it is common in many species, especially among fish.

Human predation is the hunting of people from unrelated and possibly hostile groups in order to eat them. In parts of the Southern New Guinea lowland rain forests, hunting people "was an opportunistic extension of seasonal foraging or pillaging strategies", with human bodies just as welcome as those of animals as sources of protein, according to the anthropologist Bruce M. Knauft. As populations living near coasts and rivers were usually better nourished and hence often physically larger and stronger than those living inland, they "raided inland 'bush' peoples with impunity and often with little fear of retaliation". Cases of human predation are also on record for the neighbouring Bismarck Archipelago and for Australia. In the Congo Basin, there lived groups such as the Zappo Zaps and the Bankutu who hunted humans for food even when game was plentiful.

The term innocent cannibalism has been used for cases of people eating human flesh without knowing what they are eating. It is a subject of myths, such as the myth of Thyestes who unknowingly ate the flesh of his own sons. There are also actual cases on record, for example from the Congo Basin, where cannibalism had been quite widespread and where even in the 1950s travellers were sometimes served a meat dish, learning only afterwards that the meat had been of human origin.

Gastronomic and functionalist explanations
The term gastronomic cannibalism has been suggested for cases where human flesh is eaten to "provide a supplement to the regular diet" – thus essentially for its nutritional value – or, in an alternative definition, for cases where it is "eaten without ceremony (other than culinary), in the same manner as the flesh of any other animal". While the term has been criticized as being too vague to clearly identify a specific type of cannibalism, various records indicate that nutritional or culinary concerns could indeed play a role in such acts even outside of periods of starvation. Referring to the Congo Basin, where many of the eaten were butchered slaves rather than enemies killed in war, the anthropologist Emil Torday notes that "the most common [reason for cannibalism] was simply gastronomic: the natives loved 'the flesh that speaks' [as human flesh was commonly called] and paid for it". The historian Key Ray Chong observes that, throughout Chinese history, "learned cannibalism was often practiced ... for culinary appreciation".

In his popular book Guns, Germs and Steel, Jared Diamond suggests that "protein starvation is probably also the ultimate reason why cannibalism was widespread in traditional New Guinea highland societies", and both in New Zealand and Fiji, cannibals explained their acts as due to a lack of animal meat. In Liberia, a former cannibal argued that it would have been wasteful to let the flesh of killed enemies spoil, and eaters of human flesh in New Guinea and the neighbouring Bismarck Archipelago expressed the same sentiment.

In many cases, human flesh was also described as particularly delicious, especially when it came from women, children, or both. Such statements are on record for various regions and peoples, including the Aztecs, today's Liberia and Nigeria, the Fang people in west-central Africa, the Congo Basin, China up to the 14th century, Sumatra, Borneo, Australia, New Guinea, New Zealand, and Fiji as well as various other Melanesian and Polynesian islands. Some Europeans and Americans who ate human flesh accidentally, out of curiosity, or to comply with local customs likewise tended to describe it as very good.

There is a debate among anthropologists on how important functionalist reasons are for the understanding of institutionalized cannibalism. Diamond is not alone in suggesting "that the consumption of human flesh was of nutritional benefit for some populations in New Guinea" and the same case has been made for other "tropical peoples ... exploiting a diverse range of animal foods", including human flesh. The materialist anthropologist Marvin Harris argued that a "shortage of animal protein" was also the underlying reason for Aztec cannibalism. The cultural anthropologist Marshall Sahlins, on the other hand, rejected such explanations as overly simplistic, stressing that cannibal customs must be regarded as "complex phenomen[a]" with "myriad attributes" which can only be understood if one considers "symbolism, ritual, and cosmology" in addition to their "practical function".

In pre-modern medicine, an explanation given by the now-discredited theory of humorism for cannibalism was that it was caused by a black acrimonious humor, which, being lodged in the linings of the ventricles of the heart, produced a voracity for human flesh. On the other hand, the French philosopher Michel de Montaigne understood war cannibalism as a way of expressing vengeance and hatred towards one's enemies and celebrating one's victory over them, thus giving an interpretation that is close to modern explanations. He also pointed out that some acts of Europeans in his own time could be considered as equally barbarous, making his essay "Of Cannibals" (c. 1580) a precursor to later ideas of cultural relativism.

Nutritional value of the human body
Archaeologist James Cole investigated the nutritional value of the human body and found it to be similar to that of animals of similar size. He notes that, according to ethnographic and archaeological records, nearly all edible parts of humans were sometimes eaten – not only skeletal muscle tissue ("flesh" or "meat" in a narrow sense), but also "lungs, liver, brain, heart, nervous tissue, bone marrow, genitalia and skin", as well as kidneys. For a typical adult man, the combined nutritional value of all these edible parts is about 126,000 kilocalories (kcal). The nutritional value of women and younger individuals is lower because of their lower body weight – for example, around 86% of a male adult for an adult woman and 30% for a boy aged around 5 or 6.

As the daily energy need of an adult man is about 2,400 kilocalories, a dead male body could thus have fed a group of 25 men for a bit more than two days, provided they ate nothing but the human flesh alone – longer if it was part of a mixed diet. The nutritional value of the human body is thus not insubstantial, though Cole notes that for prehistoric hunters, large megafauna such as mammoths, rhinoceros, and bisons would have been an even better deal as long as they were available and could be caught, because of their much higher body weight.

Hearts and livers
Cases of people eating human livers and hearts, especially of enemies, have been reported from across the world. After the Battle of Uhud (625), Hind bint Utba ate (or at least attempted to) the liver of Hamza ibn Abd al-Muttalib, an uncle of Muhammad. At that time, the liver was considered "the seat of life". French Catholics ate livers and hearts of Huguenots at the St. Bartholomew's Day massacre in 1572, in some cases also offering them for sale.

In China, medical cannibalism was practised over centuries. People voluntarily cut their own body parts, including parts of their livers, and boiled them to cure ailing relatives. Children were sometimes killed because eating their boiled hearts was considered a good way of extending one's life. Emperor Wuzong of Tang supposedly ordered provincial officials to send him "the hearts and livers of fifteen-year-old boys and girls" when he had become seriously ill, hoping in vain this medicine would cure him. Later private individuals sometimes followed his example, paying soldiers who kidnapped preteen children for their kitchen.

When "human flesh and organs were sold openly at the marketplace" during the Taiping Rebellion in 1850–1864, human hearts became a popular dish, according to some who afterwards freely admitted having consumed them. According to a missionary's report from the brutal suppression of the Dungan Revolt of 1895–1896 in northwestern China, "thousands of men, women and children were ruthlessly massacred by the imperial soldiers" and "many a meal of human hearts and livers was partaken of by soldiers", supposedly out of a belief that this would give them "the courage their enemies had displayed".

In World War II, Japanese soldiers ate the livers of killed Americans in the Chichijima incident. Many Japanese soldiers who died during the occupation of Jolo Island in the Philippines had their livers eaten by local Moro fighters, according to Japanese soldier Fujioka Akiyoshi.

During the Cultural Revolution (1966–1976), hundreds of incidents of cannibalism occurred, mostly motivated by hatred against supposed "class enemies", but sometimes also by health concerns. In a case recorded by the local authorities, a school teacher in Mengshan County "heard that consuming a 'beauty's heart' could cure disease". He then chose a 13- or 14-year-old student of his and publicly denounced her as a member of the enemy faction, which was enough to get her killed by an angry mob. After the others had left, he "cut open the girl's chest ..., dug out her heart, and took it home to enjoy". In a further case that took place in Wuxuan County, likewise in the Guangxi region, three brothers were beaten to death as supposed enemies; afterwards their livers were cut out, baked, and consumed "as medicine". According to the Chinese author Zheng Yi, who researched these events, "the consumption of human liver was mentioned at least fifty or sixty times" in just a small number of archival documents. He talked with a man who had eaten human liver and told him that "barbecued liver is delicious".

During a massacre of the Madurese minority in the Indonesian part of Borneo in 1999, reporter Richard Lloyd Parry met a young cannibal who had just participated in a "human barbecue" and told him without hesitation: "It tastes just like chicken. Especially the liver – just the same as chicken." In 2013, during the Syrian civil war, Syrian rebel Abu Sakkar was filmed eating parts of the lung or liver of a government soldier while declaring that "We will eat your hearts and your livers you soldiers of Bashar the dog".

Breasts, palms, and soles
Various accounts from around the world mention women's breasts as a favourite body part. Also frequently mentioned are the palms of the hands and sometimes the soles of the foots, regardless of the victim's gender.

Jerome, in his treatise Against Jovinianus, claimed that the British Attacotti were cannibals who regarded the buttocks of men and the breasts of women as delicacies. During the Mongol invasion of Europe in the 13th century and their subsequent rule over China during the Yuan dynasty (1271–1368), some Mongol fighters practised cannibalism and both European and Chinese observers record a preference for women's breasts, which were considered "delicacies" and, if there were many corpses, sometimes the only part of a female body that was eaten (of men, only the thighs were said to be eaten in such circumstances).

After meeting a group of cannibals in West Africa in the 14th century, the Moroccan explorer Ibn Battuta recorded that, according to their preferences, "the tastiest part of women's flesh is the palms and the breast." Centuries later, the anthropologist wrote that, in southern Nigeria, "the parts in greatest favour are the palms of the hands, the fingers and toes, and, of a woman, the breast." Regarding the north of the country, his colleague Charles Kingsley Meek added: "Among all the cannibal tribes the palms of the hands and the soles of the feet were considered the tit-bits of the body." Among the Apambia, a cannibalistic clan of the Azande people in Central Africa, the palms of the hands and the soles of the foots were considered the best parts of the human body, while their favourite dish was prepared with "fat from a woman's breast", according to the missionary and ethnographer F. Gero.

Similar preferences are on record throughout Melanesia. According to the anthropologists Bernard Deacon and Camilla Wedgwood, women were "specially fattened for eating" in Vanuatu, "the breasts being the great delicacy". A missionary confirmed that "a body of a female usually formed the principal part of the repast" at feasts for chiefs and warriors. The ethnologist writes: "Apart from the breasts of women and the genitals of men, palms of hands and soles of feet were the most coveted morsels." He knew a chief on Ambae, one of the islands of Vanuatu, who, "according to fairly reliably sources", dined on a young girl's breasts every few days. When visiting the Solomon Islands in the 1980s, anthropologist Michael Krieger met a former cannibal who told him that women's breasts had been considered the best part of the human body because they were so fatty, with fat being a rare and sought delicacy. They were also considered among the best parts in New Guinea and the Bismarck Archipelago.

Modes of preparation
Based on theoretical considerations, the structuralist anthropologist Claude Lévi-Strauss suggested that human flesh was most typically boiled, with roasting also used to prepare the bodies of enemies and other outsiders in exocannibalism, but rarely in funerary endocannibalism (when eating deceased relatives). But an analysis of 60 sufficiently detailed and credible descriptions of institutionalized cannibalism by anthropologist Paul Shankman failed to confirm this hypothesis. Shankman found that roasting and boiling together accounted for only about half of the cases, with roasting being slightly more common. In contrast to Lévi-Strauss's predictions, boiling was more often used in exocannibalism, while roasting was about equally common for both.

Shankman observed that various other "ways of preparing people" were repeatedly employed as well; in one third of all cases, two or more modes were used together (e.g. some bodies or body parts were boiled or baked, while others were roasted). Human flesh was baked in steam on preheated rocks or in earth ovens (a technique widely used in the Pacific), smoked (which allowed to preserve it for later consumption), or eaten raw. While these modes were used in both exo- and endocannibalism, another method that was only used in the latter and only in the Americas was to burn the bones or bodies of deceased relatives and then to consume the bone ash.

After analysing numerous accounts from China, Key Ray Chong similarly concludes that "a variety of methods for cooking human flesh" were used in this country. Most popular were "broiling, roasting, boiling and steaming", followed by "pickling in salt, wine, sauce and the like". Human flesh was also often "cooked into soup" or stewed in cauldrons. Eating human flesh raw was the "least popular" method, but a few cases are on record too. Chong notes that human flesh was typically cooked in the same way as "ordinary foodstuffs for daily consumption" – no principal distinction from the treatment of animal meat is detectable, and nearly any mode of preparation used for animals could also be used for people.

Whole-body roasting and baking
Though human corpses, like those of animals, were usually cut into pieces for further processing, reports of people being roasted or baked whole are on record throughout the world. At the archaeological site of Herxheim, Germany, more than a thousand people were killed and eaten about 7000 years ago, and the evidence indicates that many of them were spit-roasted whole over open fires.

During severe famines in China and Egypt during the 12th and early 13th centuries, there was a black-market trade in corpses of little children that were roasted or boiled whole. In China, human-flesh sellers advertised such corpses as good for being boiled or steamed whole, "including their bones", and praised their particular tenderness. In Cairo, Egypt, the Arab physician Abd al-Latif al-Baghdadi repeatedly saw "little children, roasted or boiled", offered for sale in baskets on street corners during a heavy famine that started in 1200 CE. Older children and possibly adults were sometimes prepared in the same way. Once he saw "a child nearing the age of puberty, who had been found roasted"; two young people confessed to having killed and cooked the child. Another time, remains were found of a person who had apparently been roasted and served whole, the legs tied like those of "a sheep trussed for cooking". Only the skeleton was found, still undivided and in the trussed position, but "with all the flesh stripped off for food".

In some cases children were roasted and offered for sale by their own parents; other victims were street children, who had become very numerous and were often kidnapped and cooked by people looking for food or extra income. The victims were so numerous that sometimes "two or three children, even more, would be found in a single cooking pot." Al-Latif notes that, while initially people were shocked by such acts, they "eventually ... grew accustomed, and some conceived such a taste for these detestable meats that they made them their ordinary provender ... The horror people had felt at first vanished entirely".

After the end of the Mongol-led Yuan dynasty (1271–1368), a Chinese writer criticized in his recollections of the period that some Mongol soldiers ate human flesh because of its taste rather than (as had also occurred in other times) merely in cases of necessity. He added that they enjoyed torturing their victims (often children or women, whose flesh was preferred over that of men) by roasting them alive, in "large jars whose outside touched the fire [or] on an iron grate". Other victims were placed "inside a double bag ... which was put into a large pot" and so boiled alive. While not mentioning live roasting or boiling, European authors also complained about cannibalism and cruelty during the Mongol invasion of Europe, and a drawing in the Chronica Majora (compiled by Matthew Paris) shows Mongol fighters spit-roasting a human victim.

, who accompanied Christopher Columbus during his second voyage, afterwards stated "that he saw there with his own eyes several Indians skewered on spits being roasted over burning coals as a treat for the gluttonous." Jean de Léry, who lived for several months among the Tupinambá in Brazil, writes that several of his companions reported "that they had seen not only a number of men and women cut in pieces and grilled on the boucans, but also little unweaned children roasted whole" after a successful attack on an enemy village.

According to German ethnologist Leo Frobenius, children captured by Songye slave raiders in the Central African Kasaï region that were too young to be sold with a profit were instead "skewered on long spears like rats and roasted over a quickly kindled large fire" for consumption by the raiders.

In the Solomon Islands in the 1870s, a British captain saw a "dead body, dressed and cooked whole" offered for sale in a canoe. A settler treated the scene as "an every-day occurrence" and told him "that he had seen as many as twenty bodies lying on the beach, dressed and cooked". Decades later, a missionary reported that whole bodies were still offered "up and down the coast in canoes for sale" after battles, since human flesh was eaten "for pleasure".

In Fiji, whole human bodies cooked in earth ovens were served in carefully pre-arranged postures, according to anthropologist Lorimer Fison and several other sources:

"The limbs having been arranged in the posture which it is intended they shall assume, banana leaves are wrapped round them to prevent the flesh falling off in the possible event of over-baking.... A hole of sufficient size is then dug in the earth, and filled with dry wood, which is set on fire. When it is well kindled, a number of stones, about the size of a man's fist, are thrown into it; and when the firewood is burnt down to a mass of glowing embers, some of the heated stones are lifted nimbly by tongs made of bent withes, and thrust within the dead man's body.... Presently the mound swells and rises; little cracks appear, whence issue jets of steam diffusing a savoury odour; and in due time, of which the Fijians are excellent judges, the culinary process is complete. The earth is then cautiously removed, the body lifted out, its wrappings taken off, its face painted, a wig or a turban placed upon its head, and there we have a 'trussed frog' [as such steamed corpses were called] in all its unspeakable hideousness, staring at us with wide open, prominent, lack-lustre eyes. There is no burning or roasting: the body is cooked in its own steam, and the features are so little disturbed by the process that the dead man can almost always be recognised by those who knew him when he was alive."

Within this archipelago, it was especially the Gau Islanders who "were famous for cooking bodies whole".

In New Caledonia, a missionary named Ta'unga from the Cook Islands repeatedly saw how whole human bodies were cooked in earth ovens: "They tie the hands together and bundle them up together with the intestines. The legs are bent up and bound with hibiscus bark. When it is completed they lay the body out flat on its back in the earth oven, then when it is baked ready they cut it up and eat it." Ta'unga commented: "One curious thing is that when a man is alive he has a human appearance, but after he is baked he looks more like a dog, as the lips are shriveled back and his teeth are bared."

Among the Māori in New Zealand, children captured in war campaigns were sometimes spit-roasted whole (after slitting open their bellies to remove the intestines), as various sources report. Enslaved children, including teenagers, could meet the same fate, and whole babies were sometimes served at the tables of chiefs.

In the Marquesas Islands, captives (preferably women) killed for consumption "were spitted on long poles that entered between their legs and emerged from their mouths" and then roasted whole. Similar customs had a long history: In Nuku Hiva, the largest of these islands, archaeologists found the partially consumed "remains of a young child" that had been roasted whole in an oven during the 14th century or earlier.

Medical aspects
A well-known case of mortuary cannibalism is that of the Fore tribe in New Guinea, which resulted in the spread of the prion disease kuru. Although the Fore's mortuary cannibalism was well-documented, the practice had ceased before the cause of the disease was recognized. However, some scholars argue that although post-mortem dismemberment was the practice during funeral rites, cannibalism was not. Marvin Harris theorizes that it happened during a famine period coincident with the arrival of Europeans and was rationalized as a religious rite.

In 2003, a publication in Science received a large amount of press attention when it suggested that early humans may have practised extensive cannibalism. According to this research, genetic markers commonly found in modern humans worldwide suggest that today many people carry a gene that evolved as protection against the brain diseases that can be spread by consuming human brain tissue. A 2006 reanalysis of the data questioned this hypothesis, because it claimed to have found a data collection bias, which led to an erroneous conclusion. This claimed bias came from incidents of cannibalism used in the analysis not being due to local cultures, but having been carried out by explorers, stranded seafarers or escaped convicts. The original authors published a subsequent paper in 2008 defending their conclusions.

Myths, legends and folklore

Cannibalism features in the folklore and legends of many cultures and is most often attributed to evil characters or as extreme retribution for some wrongdoing. Examples include the witch in "Hansel and Gretel", Lamia of Greek mythology and the witch Baba Yaga of Slavic folklore.

A number of stories in Greek mythology involve cannibalism, in particular the eating of close family members, e.g., the stories of Thyestes, Tereus and especially Cronus, who became Saturn in the Roman pantheon. The story of Tantalus is another example, though here a family member is prepared for consumption by others.

The wendigo is a creature appearing in the legends of the Algonquian people. It is thought of variously as a malevolent cannibalistic spirit that could possess humans or a monster that humans could physically transform into. Those who indulged in cannibalism were at particular risk, and the legend appears to have reinforced this practice as taboo. The Zuni people tell the story of the Átahsaia – a giant who cannibalizes his fellow demons and seeks out human flesh.

The wechuge is a demonic cannibalistic creature that seeks out human flesh appearing in the mythology of the Athabaskan people. It is said to be half monster and half human-like; however, it has many shapes and forms.

Scepticism
William Arens, author of The Man-Eating Myth: Anthropology and Anthropophagy, questions the credibility of reports of cannibalism and argues that the description by one group of people of another people as cannibals is a consistent and demonstrable ideological and rhetorical device to establish perceived cultural superiority. Arens bases his thesis on a detailed analysis of various "classic" cases of cannibalism reported by explorers, missionaries, and anthropologists. He claims that all of them were steeped in racism, unsubstantiated, or based on second-hand or hearsay evidence. Though widely discussed, Arens's book generally failed to convince the academic community. Claude Lévi-Strauss observes that, in spite of his "brilliant but superficial book ... [n]o serious ethnologist disputes the reality of cannibalism". Shirley Lindenbaum notes that, while after "Arens['s] ... provocative suggestion ... many anthropologists ... reevaluated their data", the outcome was an improved and "more nuanced" understanding of where, why and under which circumstances cannibalism took place rather than a confirmation of his claims: "Anthropologists working in the Americas, Africa, and Melanesia now acknowledge that institutionalized cannibalism occurred in some places at some times. Archaeologists and evolutionary biologists are taking cannibalism seriously."

Lindenbaum and others point out that Arens displays a "strong ethnocentrism". His refusal to admit that institutionalized cannibalism ever existed seems to be motivated by the implied idea "that cannibalism is the worst thing of all" – worse than any other behaviour people engaged in, and therefore uniquely suited to vilifying others. Kajsa Ekholm Friedman calls this "a remarkable opinion in a culture [the European/American one] that has been capable of the most extreme cruelty and destructive behavior, both at home and in other parts of the world."

She observes that, contrary to European values and expectations, "in many parts of the Congo region there was no negative evaluation of cannibalism. On the contrary, people expressed their strong appreciation of this very special meat and could not understand the hysterical reactions from the white man's side." And why indeed, she goes on to ask, should they have had the same negative reactions to cannibalism as Arens and his contemporaries? Implicitly he assumes that everybody throughout human history must have shared the strong taboo placed by his own culture on cannibalism, but he never attempts to explain why this should be so, and "neither logic nor historical evidence justifies" this viewpoint, as Christian Siefkes commented.

Some have argued that it is the taboo against cannibalism, rather than its practice, that needs to be explained. Hubert Murray, the Lieutenant-Governor of Papua in the early 20th century, admitted that "I have never been able to give a convincing answer to a native who says to me, 'Why should I not eat human flesh? After observing that the Orokaiva people in New Guinea explained their cannibal customs as due to "a simple desire for good food", the Australian anthropologist F. E. Williams commented: "Anthropologically speaking the fact that we ourselves should persist in a superstitious, or at least sentimental, prejudice against human flesh is more puzzling than the fact that the Orokaiva, a born hunter, should see fit to enjoy perfectly good meat when he gets it."

Accusations of cannibalism could be used to characterize indigenous peoples as "uncivilized", "primitive", or even "inhuman." While this means that the reliability of reports of cannibal practices must be carefully evaluated especially if their wording suggests such a context, many actual accounts do not fit this pattern. The earliest firsthand account of cannibal customs in the Caribbean comes from Diego Álvarez Chanca, who accompanied Christopher Columbus on his second voyage. His description of the customs of the Caribs of Guadeloupe includes their cannibalism (men killed or captured in war were eaten, while captured boys were "castrated [and used as] servants until they gr[e]w up, when they [were] slaughtered" for consumption), but he nevertheless notes "that these people are more civilized than the other islanders" (who did not practice cannibalism). Nor was he an exception. Among the earliest reports of cannibalism in the Caribbean and the Americas, there are some (like those of Amerigo Vespucci) that seem to mostly consist of hearsay and "gross exaggerations", but others (by Chanca, Columbus himself, and other early travellers) show "genuine interest and respect for the natives" and include "numerous cases of sincere praise".

Reports of cannibalism from other continents follow similar patterns. Condescending remarks can be found, but many Europeans who described cannibal customs in Central Africa wrote about those who practised them in quite positive terms, calling them "splendid" and "the finest people" and not rarely, like Chanca, actually considering them as "far in advance of" and "intellectually and morally superior" to the non-cannibals around them. Writing from Melanesia, the missionary George Brown explicitly rejects the European prejudice of picturing cannibals as "particularly ferocious and repulsive", noting instead that many cannibals he met were "no more ferocious than" others and "indeed ... very nice people".

Reports or assertions of cannibal practices could nevertheless be used to promote the use of military force as a means of "civilizing" and "pacifying" the "savages". During the Spanish conquest of the Aztec Empire and its earlier conquests in the Caribbean there were widespread reports of cannibalism, and cannibals became exempted from Queen Isabella's prohibition on enslaving the indigenous. Another example of the sensationalism of cannibalism and its connection to imperialism occurred during Japan's 1874 expedition to Taiwan. As Robert Eskildsen describes, Japan's popular media "exaggerated the aborigines' violent nature", in some cases by wrongly accusing them of cannibalism.

This Horrid Practice: The Myth and Reality of Traditional Maori Cannibalism (2008) by New Zealand historian Paul Moon received a hostile reception by some Māori, who felt the book tarnished their whole people. However, the factual accuracy of the book was not seriously disputed and even critics such as Margaret Mutu grant that cannibalism was "definitely" practised and that it was "part of our [Māori] culture."

History
There is archaeological evidence that cannibalism has been practised for at least hundreds of thousands of years by early Homo sapiens and archaic hominins. Among modern humans, cannibalism has been practised by various groups. An incomplete list of cases where it is documented to have occurred in institutionalized form includes prehistoric and early modern Europe, South America, Mesoamerica, Iroquoian peoples in North America, parts of Western and Central Africa, China and Sumatra, among pre-contact Aboriginal Australians, among Māori in New Zealand, on some other Polynesian islands as well as in New Guinea, the Solomon Islands, and Fiji. Evidence of cannibalism has also been found in ruins associated with the Ancestral Puebloans, at Cowboy Wash in the Southwestern United States.

After World War I, institutionalized cannibalism has become very rare, but cases were still reported during times of famine. Occasional cannibal acts committed by individual criminals also are documented throughout the 20th and 21st centuries.

title: Human cannibalism


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Chemical element

A chemical element is a chemical substance that cannot be broken down into other substances by chemical reactions. The basic particle that constitutes a chemical element is the atom. Elements are identified by the number of protons in their nucleus, known as the element's atomic number. For example, oxygen has an atomic number of 8, meaning each oxygen atom has 8 protons in its nucleus. Atoms of the same element can have different numbers of neutrons in their nuclei, known as isotopes of the element. Two or more atoms can combine to form molecules. Chemical compounds are molecules made of atoms of different elements, while mixtures contain atoms of different elements not necessarily combined as molecules. Atoms can be transformed into different elements in nuclear reactions, which change an atom's atomic number.

Almost all baryonic matter in the universe is composed of elements (among rare exceptions are neutron stars). When different elements undergo chemical reactions, atoms are rearranged into new compounds held together by chemical bonds. Only a few elements, such as silver and gold, are found uncombined as relatively pure native element minerals. Nearly all other naturally occurring elements occur in the Earth as compounds or mixtures. Air is mostly a mixture of molecular nitrogen and oxygen, though it does contain compounds including carbon dioxide and water, as well as atomic argon, a noble gas which is chemically inert and therefore does not undergo chemical reactions.

The history of the discovery and use of elements began with early human societies that discovered native minerals like carbon, sulfur, copper and gold (though the modern concept of an element was not yet understood). Attempts to classify materials such as these resulted in the concepts of classical elements, alchemy, and similar theories throughout history. Much of the modern understanding of elements developed from the work of Dmitri Mendeleev, a Russian chemist who published the first recognizable periodic table in 1869. This table organizes the elements by increasing atomic number into rows ("periods") in which the columns ("groups") share recurring ("periodic") physical and chemical properties. The periodic table summarizes various properties of the elements, allowing chemists to derive relationships between them and to make predictions about elements not yet discovered, and potential new compounds.

By November 2016, the International Union of Pure and Applied Chemistry (IUPAC) had recognized a total of 118 elements. The first 94 occur naturally on Earth, and the remaining 24 are synthetic elements produced in nuclear reactions. Save for unstable radioactive elements (radioelements) which decay quickly, nearly all elements are available industrially in varying amounts. The discovery and synthesis of further new elements is an ongoing area of scientific study.

Description
The lightest elements are hydrogen and helium, both created by Big Bang nucleosynthesis in the first 20 minutes of the universe in a ratio of around 3:1 by mass (or 12:1 by number of atoms), along with tiny traces of the next two elements, lithium and beryllium. Almost all other elements found in nature were made by various natural methods of nucleosynthesis. On Earth, small amounts of new atoms are naturally produced in nucleogenic reactions, or in cosmogenic processes, such as cosmic ray spallation. New atoms are also naturally produced on Earth as radiogenic daughter isotopes of ongoing radioactive decay processes such as alpha decay, beta decay, spontaneous fission, cluster decay, and other rarer modes of decay.

Of the 94 naturally occurring elements, those with atomic numbers 1 through 82 each have at least one stable isotope (except for technetium, element 43 and promethium, element 61, which have no stable isotopes). Isotopes considered stable are those for which no radioactive decay has yet been observed. Elements with atomic numbers 83 through 94 are unstable to the point that radioactive decay of all isotopes can be detected. Some of these elements, notably bismuth (atomic number 83), thorium (atomic number 90), and uranium (atomic number 92), have one or more isotopes with half-lives long enough to survive as remnants of the explosive stellar nucleosynthesis that produced the heavy metals before the formation of our Solar System. At over 1.9 years, over a billion times longer than the estimated age of the universe, bismuth-209 has the longest known alpha decay half-life of any isotope, and is almost always considered on par with the 80 stable elements. The heaviest elements (those beyond plutonium, element 94) undergo radioactive decay with half-lives so short that they are not found in nature and must be synthesized.

There are now 118 known elements. In this context, "known" means observed well enough, even from just a few decay products, to have been differentiated from other elements. Most recently, the synthesis of element 118 (since named oganesson) was reported in October 2006, and the synthesis of element 117 (tennessine) was reported in April 2010. Of these 118 elements, 94 occur naturally on Earth. Six of these occur in extreme trace quantities: technetium, atomic number 43; promethium, number 61; astatine, number 85; francium, number 87; neptunium, number 93; and plutonium, number 94. These 94 elements have been detected in the universe at large, in the spectra of stars and also supernovae, where short-lived radioactive elements are newly being made. The first 94 elements have been detected directly on Earth as primordial nuclides present from the formation of the Solar System, or as naturally occurring fission or transmutation products of uranium and thorium.

The remaining 24 heavier elements, not found today either on Earth or in astronomical spectra, have been produced artificially: all are radioactive, with short half-lives; if any of these elements were present at the formation of Earth, they are certain to have completely decayed, and if present in novae, are in quantities too small to have been noted. Technetium was the first purportedly non-naturally occurring element synthesized, in 1937, though trace amounts of technetium have since been found in nature (and also the element may have been discovered naturally in 1925). This pattern of artificial production and later natural discovery has been repeated with several other radioactive naturally occurring rare elements.

List of the elements are available by name, atomic number, density, melting point, boiling point and chemical symbol, as well as ionization energy. The nuclides of stable and radioactive elements are also available as a list of nuclides, sorted by length of half-life for those that are unstable. One of the most convenient, and certainly the most traditional presentation of the elements, is in the form of the periodic table, which groups together elements with similar chemical properties (and usually also similar electronic structures).

Atomic number
The atomic number of an element is equal to the number of protons in each atom, and defines the element. For example, all carbon atoms contain 6 protons in their atomic nucleus; so the atomic number of carbon is 6. Carbon atoms may have different numbers of neutrons; atoms of the same element having different numbers of neutrons are known as isotopes of the element.

The number of protons in the nucleus also determines its electric charge, which in turn determines the number of electrons of the atom in its non-ionized state. The electrons are placed into atomic orbitals that determine the atom's chemical properties. The number of neutrons in a nucleus usually has very little effect on an element's chemical properties; except for hydrogen (for which the kinetic isotope effect is significant). Thus, all carbon isotopes have nearly identical chemical properties because they all have six electrons, even though they may have 6 to 8 neutrons. That is why atomic number, rather than mass number or atomic weight, is considered the identifying characteristic of an element.

The symbol for atomic number is Z.

Isotopes
Isotopes are atoms of the same element (that is, with the same number of protons in their nucleus), but having different numbers of neutrons. Thus, for example, there are three main isotopes of carbon. All carbon atoms have 6 protons, but they can have either 6, 7, or 8 neutrons. Since the mass numbers of these are 12, 13 and 14 respectively, said three isotopes are known as carbon-12, carbon-13, and carbon-14 ($12$C, $13$C, and $14$C). Natural carbon is a mixture of $12$C (about 98.9%), $13$C (about 1.1%) and about 1 atom per trillion of $14$C.

Most (66 of 94) naturally occurring elements have more than one stable isotope. Except for the isotopes of hydrogen (which differ greatly from each other in relative mass—enough to cause chemical effects), the isotopes of a given element are chemically nearly indistinguishable.

All elements have radioactive isotopes (radioisotopes); most of these radioisotopes do not occur naturally. Radioisotopes typically decay into other elements via alpha decay, beta decay, or inverse beta decay; some isotopes of the heaviest elements also undergo spontaneous fission. Isotopes that are not radioactive, are termed "stable" isotopes. All known stable isotopes occur naturally (see primordial nuclide). The many radioisotopes that are not found in nature have been characterized after being artificially produced. Certain elements have no stable isotopes and are composed only of radioisotopes: specifically the elements without any stable isotopes are technetium (atomic number 43), promethium (atomic number 61), and all observed elements with atomic number greater than 82.

Of the 80 elements with at least one stable isotope, 26 have only one stable isotope. The mean number of stable isotopes for the 80 stable elements is 3.1 stable isotopes per element. The largest number of stable isotopes for a single element is 10 (for tin, element 50).

Isotopic mass and atomic mass
The mass number of an element, A, is the number of nucleons (protons and neutrons) in the atomic nucleus. Different isotopes of a given element are distinguished by their mass number, which is written as a superscript on the left hand side of the chemical symbol (e.g., $238$U). The mass number is always an integer and has units of "nucleons". Thus, magnesium-24 (24 is the mass number) is an atom with 24 nucleons (12 protons and 12 neutrons).

Whereas the mass number simply counts the total number of neutrons and protons and is thus an integer, the atomic mass of a particular isotope (or "nuclide") of the element is the mass of a single atom of that isotope, and is typically expressed in daltons (symbol: Da), or universal atomic mass units (symbol: u). Its relative atomic mass is a dimensionless number equal to the atomic mass divided by the atomic mass constant, which equals 1 Da. In general, the mass number of a given nuclide differs in value slightly from its relative atomic mass, since the mass of each proton and neutron is not exactly 1 Da; since the electrons contribute a lesser share to the atomic mass as neutron number exceeds proton number; and because of the nuclear binding energy and electron binding energy. For example, the atomic mass of chlorine-35 to five significant digits is 34.969 Da and that of chlorine-37 is 36.966 Da. However, the relative atomic mass of each isotope is quite close to its mass number (always within 1%). The only isotope whose atomic mass is exactly a natural number is $12$C, which has a mass of 12 Da; because the dalton is defined as 1/12 of the mass of a free neutral carbon-12 atom in the ground state.

The standard atomic weight (commonly called "atomic weight") of an element is the average of the atomic masses of all the chemical element's isotopes as found in a particular environment, weighted by isotopic abundance, relative to the atomic mass unit. This number may be a fraction that is not close to a whole number. For example, the relative atomic mass of chlorine is 35.453 u, which differs greatly from a whole number as it is an average of about 76% chlorine-35 and 24% chlorine-37. Whenever a relative atomic mass value differs by more than ~1% from a whole number, it is due to this averaging effect, as significant amounts of more than one isotope are naturally present in a sample of that element.

Chemically pure and isotopically pure
Chemists and nuclear scientists have different definitions of a pure element. In chemistry, a pure element means a substance whose atoms all (or in practice almost all) have the same atomic number, or number of protons. Nuclear scientists, however, define a pure element as one that consists of only one isotope.

For example, a copper wire is 99.99% chemically pure if 99.99% of its atoms are copper, with 29 protons each. However it is not isotopically pure since ordinary copper consists of two stable isotopes, 69% $63$Cu and 31% $65$Cu, with different numbers of neutrons. However, pure gold would be both chemically and isotopically pure, since ordinary gold consists only of one isotope, $197$Au.

Allotropes
Atoms of chemically pure elements may bond to each other chemically in more than one way, allowing the pure element to exist in multiple chemical structures (spatial arrangements of atoms), known as allotropes, which differ in their properties. For example, carbon can be found as diamond, which has a tetrahedral structure around each carbon atom; graphite, which has layers of carbon atoms with a hexagonal structure stacked on top of each other; graphene, which is a single layer of graphite that is very strong; fullerenes, which have nearly spherical shapes; and carbon nanotubes, which are tubes with a hexagonal structure (even these may differ from each other in electrical properties). The ability of an element to exist in one of many structural forms is known as 'allotropy'.

The reference state of an element is defined by convention, usually as the thermodynamically most stable allotrope and physical state at a pressure of 1 bar and a given temperature (typically at 298.15K). However, for phosphorus, the reference state is white phosphorus even though it is not the most stable allotrope, and the reference state for carbon is graphite, because the structure of graphite is more stable than that of the other allotropes. In thermochemistry, an element is defined to have an enthalpy of formation of zero in its reference state.

Properties
Several kinds of descriptive categorizations can be applied broadly to the elements, including consideration of their general physical and chemical properties, their states of matter under familiar conditions, their melting and boiling points, their densities, their crystal structures as solids, and their origins.

General properties
Several terms are commonly used to characterize the general physical and chemical properties of the chemical elements. A first distinction is between metals, which readily conduct electricity, nonmetals, which do not, and a small group, (the metalloids), having intermediate properties and often behaving as semiconductors.

A more refined classification is often shown in colored presentations of the periodic table. This system restricts the terms "metal" and "nonmetal" to only certain of the more broadly defined metals and nonmetals, adding additional terms for certain sets of the more broadly viewed metals and nonmetals. The version of this classification used in the periodic tables presented here includes: actinides, alkali metals, alkaline earth metals, halogens, lanthanides, transition metals, post-transition metals, metalloids, reactive nonmetals, and noble gases. In this system, the alkali metals, alkaline earth metals, and transition metals, as well as the lanthanides and the actinides, are special groups of the metals viewed in a broader sense. Similarly, the reactive nonmetals and the noble gases are nonmetals viewed in the broader sense. In some presentations, the halogens are not distinguished, with astatine identified as a metalloid and the others identified as nonmetals.

States of matter
Another commonly used basic distinction among the elements is their state of matter (phase), whether solid, liquid, or gas, at standard temperature and pressure (STP). Most elements are solids at STP, while several are gases. Only bromine and mercury are liquid at 0 degrees Celsius (32 degrees Fahrenheit) and 1 atmosphere pressure; caesium and gallium are solid at that temperature, but melt at 28.4°C (83.2°F) and 29.8°C (85.6°F), respectively.

Melting and boiling points
Melting and boiling points, typically expressed in degrees Celsius at a pressure of one atmosphere, are commonly used in characterizing the various elements. While known for most elements, either or both of these measurements is still undetermined for some of the radioactive elements available in only tiny quantities. Since helium remains a liquid even at absolute zero at atmospheric pressure, it has only a boiling point, and not a melting point, in conventional presentations.

Densities
The density at selected standard temperature and pressure (STP) is often used in characterizing the elements. Density is often expressed in grams per cubic centimetre (g/cm$3$). Since several elements are gases at commonly encountered temperatures, their densities are usually stated for their gaseous forms; when liquefied or solidified, the gaseous elements have densities similar to those of the other elements.

When an element has allotropes with different densities, one representative allotrope is typically selected in summary presentations, while densities for each allotrope can be stated where more detail is provided. For example, the three familiar allotropes of carbon (amorphous carbon, graphite, and diamond) have densities of 1.8–2.1, 2.267, and 3.515 g/cm$3$, respectively.

Crystal structures
The elements studied to date as solid samples have eight kinds of crystal structures: cubic, body-centered cubic, face-centered cubic, hexagonal, monoclinic, orthorhombic, rhombohedral, and tetragonal. For some of the synthetically produced transuranic elements, available samples have been too small to determine crystal structures.

Occurrence and origin on Earth
Chemical elements may also be categorized by their origin on Earth, with the first 94 considered naturally occurring, while those with atomic numbers beyond 94 have only been produced artificially via human-made nuclear reactions.

Of the 94 naturally occurring elements, 83 are considered primordial and either stable or weakly radioactive. The longest-lived isotopes of the remaining 11 elements have half lives too short for them to have been present at the beginning of the Solar System, and are therefore considered transient elements. Of these 11 transient elements, five (polonium, radon, radium, actinium, and protactinium) are relatively common decay products of thorium and uranium. The remaining six transient elements (technetium, promethium, astatine, francium, neptunium, and plutonium) occur only rarely, as products of rare decay modes or nuclear reaction processes involving uranium or other heavy elements.

Elements with atomic numbers 1 through 82, except 43 (technetium) and 61 (promethium), each have at least one isotope for which no radioactive decay has been observed. Observationally stable isotopes of some elements (such as tungsten and lead), however, are predicted to be slightly radioactive with very long half-lives: for example, the half-lives predicted for the observationally stable lead isotopes range from 10$35$ to 10$189$ years. Elements with atomic numbers 43, 61, and 83 through 94 are unstable enough that their radioactive decay can be detected. Three of these elements, bismuth (element 83), thorium (90), and uranium (92) have one or more isotopes with half-lives long enough to survive as remnants of the explosive stellar nucleosynthesis that produced the heavy elements before the formation of the Solar System. For example, at over 1.9 years, over a billion times longer than the estimated age of the universe, bismuth-209 has the longest known alpha decay half-life of any isotope. The last 24 elements (those beyond plutonium, element 94) undergo radioactive decay with short half-lives and cannot be produced as daughters of longer-lived elements, and thus are not known to occur in nature at all.

Periodic table
The properties of the elements are often summarized using the periodic table, which powerfully and elegantly organizes the elements by increasing atomic number into rows ("periods") in which the columns ("groups") share recurring ("periodic") physical and chemical properties. The table contains 118 confirmed elements as of 2021.

Although earlier precursors to this presentation exist, its invention is generally credited to Russian chemist Dmitri Mendeleev in 1869, who intended the table to illustrate recurring trends in the properties of the elements. The layout of the table has been refined and extended over time as new elements have been discovered and new theoretical models have been developed to explain chemical behavior.

Use of the periodic table is now ubiquitous in chemistry, providing an extremely useful framework to classify, systematize and compare all the many different forms of chemical behavior. The table has also found wide application in physics, geology, biology, materials science, engineering, agriculture, medicine, nutrition, environmental health, and astronomy. Its principles are especially important in chemical engineering.

Nomenclature and symbols
The various chemical elements are formally identified by their unique atomic numbers, their accepted names, and their chemical symbols.

Atomic numbers
The known elements have atomic numbers from 1 to 118, conventionally presented as Arabic numerals. Since the elements can be uniquely sequenced by atomic number, conventionally from lowest to highest (as in a periodic table), sets of elements are sometimes specified by such notation as "through", "beyond", or "from ... through", as in "through iron", "beyond uranium", or "from lanthanum through lutetium". The terms "light" and "heavy" are sometimes also used informally to indicate relative atomic numbers (not densities), as in "lighter than carbon" or "heavier than lead", though the atomic masses of the elements (their atomic weights or atomic masses) do not always increase monotonically with their atomic numbers.

Element names
The naming of various substances now known as elements precedes the atomic theory of matter, as names were given locally by various cultures to various minerals, metals, compounds, alloys, mixtures, and other materials, though at the time it was not known which chemicals were elements and which compounds. As they were identified as elements, the existing names for anciently known elements (e.g., gold, mercury, iron) were kept in most countries. National differences emerged over the element names either for convenience, linguistic niceties, or nationalism. For example, German speakers use "Wasserstoff" (water substance) for "hydrogen", "Sauerstoff" (acid substance) for "oxygen" and "Stickstoff" (smothering substance) for "nitrogen"; English and some other languages use "sodium" for "natrium", and "potassium" for "kalium"; and the French, Italians, Greeks, Portuguese and Poles prefer "azote/azot/azoto" (from roots meaning "no life") for "nitrogen".

For purposes of international communication and trade, the official names of the chemical elements both ancient and more recently recognized are decided by the International Union of Pure and Applied Chemistry (IUPAC), which has decided on a sort of international English language, drawing on traditional English names even when an element's chemical symbol is based on a Latin or other traditional word, for example adopting "gold" rather than "aurum" as the name for the 79th element (Au). IUPAC prefers the British spellings "aluminium" and "caesium" over the U.S. spellings "aluminum" and "cesium", and the U.S. "sulfur" over British "sulphur". However, elements that are practical to sell in bulk in many countries often still have locally used national names, and countries whose national language does not use the Latin alphabet are likely to use the IUPAC element names.

According to IUPAC, element names are not proper nouns; therefore, the full name of an element is not capitalized in English, even if derived from a proper noun, as in californium and einsteinium. Isotope names are also uncapitalized if written out, e.g., carbon-12 or uranium-235. Chemical element symbols (such as Cf for californium and Es for einsteinium), are always capitalized (see below).

In the second half of the 20th century, physics laboratories became able to produce elements with half-lives too short for an appreciable amount of them to exist at any time. These are also named by IUPAC, which generally adopts the name chosen by the discoverer. This practice can lead to the controversial question of which research group actually discovered an element, a question that delayed the naming of elements with atomic number of 104 and higher for a considerable amount of time. (See element naming controversy).

Precursors of such controversies involved the nationalistic namings of elements in the late 19th century. For example, lutetium was named in reference to Paris, France. The Germans were reluctant to relinquish naming rights to the French, often calling it cassiopeium. Similarly, the British discoverer of niobium originally named it columbium, in reference to the New World. It was used extensively as such by American publications before the international standardization (in 1950).

Specific elements
Before chemistry became a science, alchemists designed arcane symbols for both metals and common compounds. These were however used as abbreviations in diagrams or procedures; there was no concept of atoms combining to form molecules. With his advances in the atomic theory of matter, John Dalton devised his own simpler symbols, based on circles, to depict molecules.

The current system of chemical notation was invented by Jöns Jacob Berzelius in 1814. In this system, chemical symbols are not mere abbreviations—though each consists of letters of the Latin alphabet. They are intended as universal symbols for people of all languages and alphabets.

Since Latin was the common language of science at Berzelius' time, his symbols were abbreviations based on the Latin names of elements (they may be Classical Latin names of elements known since antiquity or Neo-Latin coinages for later elements). The symbols are not followed by a period (full stop) as with abbreviations. In most cases, Latin names of elements as used by Berzelius have the same roots as the modern English name. For example, hydrogen has the symbol "H" from Neo-Latin hydrogenium, which has the same Greek roots as English hydrogen. However, in eleven cases Latin (as used by Berzelius) and English names of elements have different roots. Eight of them are the seven metals of antiquity and a metalloid also known since antiquity: "Fe" (Latin ferrum) for iron, "Hg" (Latin hydrargyrum) for mercury, "Sn" (Latin stannum) for tin, "Au" (Latin aurum) for gold, "Ag" (Latin argentum) for silver, "Pb" (Latin plumbum) for lead, "Cu" (Latin cuprum) for copper, and "Sb" (Latin stibium) for antimony. The three other mismatches between Neo-Latin (as used by Berzelius) and English names are "Na" (Neo-Latin natrium) for sodium, "K" (Neo-Latin kalium) for potassium, and "W" (Neo-Latin wolframium) for tungsten. These mismatches came from different suggestings of naming the elements in the Modern era. Initially Berzelius had suggested "So" and "Po" for sodium and potassium, but he changed the symbols to "Na" and "K" later in the same year.

Elements discovered after 1814 were also assigned unique chemical symbols, based on the name of the element. The use of Latin as the universal language of science was fading, but chemical names of newly discovered elements came to be borrowed from language to language with little or no modifications. Symbols of elements discovered after 1814 match their names in English, French (ignoring the acute accent on $\langleé\rangle$), and German (though German often allows alternate spellings with $\langlek\rangle$ or $\langlez\rangle$ instead of $\langlec\rangle$: e.g., the name of calcium may be spelled Calcium or Kalzium in German, but its symbol is always "Ca"). Other languages sometimes modify element name spellings: Spanish iterbio (ytterbium), Italian afnio (hafnium), Swedish moskovium (moscovium); but those modifications do not affect chemical symbols: Yb, Hf, Mc.

Chemical symbols are understood internationally when element names might require translation. There have been some differences in the past. For example, Germans in the past have used "J" (for the name Jod) for iodine, but now use "I" and Iod.

The first letter of a chemical symbol is always capitalized, as in the preceding examples, and the subsequent letters, if any, are always lower case. Thus, the symbols for californium and einsteinium are Cf and Es.

General chemical symbols
There are also symbols in chemical equations for groups of elements, for example in comparative formulas. These are often a single capital letter, and the letters are reserved and not used for names of specific elements. For example, "X" indicates a variable group (usually a halogen) in a class of compounds, while "R" is a radical, meaning a compound structure such as a hydrocarbon chain. The letter "Q" is reserved for "heat" in a chemical reaction. "Y" is also often used as a general chemical symbol, though it is also the symbol of yttrium. "Z" is also often used as a general variable group. "E" is used in organic chemistry to denote an electron-withdrawing group or an electrophile; similarly "Nu" denotes a nucleophile. "L" is used to represent a general ligand in inorganic and organometallic chemistry. "M" is also often used in place of a general metal.

At least two other, two-letter generic chemical symbols are also in informal use, "Ln" for any lanthanide and "An" for any actinide. "Rg" was formerly used for any rare gas element, but the group of rare gases has now been renamed noble gases and "Rg" now refers to roentgenium.

Isotope symbols
Isotopes of an element are distinguished by mass number (total protons and neutrons), with this number combined with the element's symbol. IUPAC prefers that isotope symbols be written in superscript notation when practical, for example $12$C and $235$U. However, other notations, such as carbon-12 and uranium-235, or C-12 and U-235, are also used.

As a special case, the three naturally occurring isotopes of hydrogen are often specified as H for $1$H (protium), D for $2$H (deuterium), and T for $3$H (tritium). This convention is easier to use in chemical equations, replacing the need to write out the mass number each time. Thus, the formula for heavy water may be written D$2$O instead of $2$H$2$O.

Origin of the elements

Only about 4% of the total mass of the universe is made of atoms or ions, and thus represented by elements. This fraction is about 15% of the total matter, with the remainder of the matter (85%) being dark matter. The nature of dark matter is unknown, but it is not composed of atoms of elements because it contains no protons, neutrons, or electrons. (The remaining non-matter part of the mass of the universe is composed of the even less well understood dark energy).

The 94 naturally occurring elements were produced by at least four classes of astrophysical process. Most of the hydrogen, helium and a very small quantity of lithium were produced in the first few minutes of the Big Bang. This Big Bang nucleosynthesis happened only once; the other processes are ongoing. Nuclear fusion inside stars produces elements through stellar nucleosynthesis, including all elements from carbon to iron in atomic number. Elements higher in atomic number than iron, including heavy elements like uranium and plutonium, are produced by various forms of explosive nucleosynthesis in supernovae and neutron star mergers. The light elements lithium, beryllium and boron are produced mostly through cosmic ray spallation (fragmentation induced by cosmic rays) of carbon, nitrogen, and oxygen.

In the early phases of the Big Bang, nucleosynthesis of hydrogen resulted in the production of hydrogen-1 (protium, $1$H) and helium-4 ($4$He), as well as a smaller amount of deuterium ($2$H) and tiny amounts (on the order of 10$−10$) of lithium and beryllium. Even smaller amounts of boron may have been produced in the Big Bang, since it has been observed in some very old stars, while carbon has not. No elements heavier than boron were produced in the Big Bang. As a result, the primordial abundance of atoms (or ions) consisted of ~75% $1$H, 25% $4$He, and 0.01% deuterium, with only tiny traces of lithium, beryllium, and perhaps boron. Subsequent enrichment of galactic halos occurred due to stellar nucleosynthesis and supernova nucleosynthesis. However, the element abundance in intergalactic space can still closely resemble primordial conditions, unless it has been enriched by some means.

On Earth (and elsewhere), trace amounts of various elements continue to be produced from other elements as products of nuclear transmutation processes. These include some produced by cosmic rays or other nuclear reactions (see cosmogenic and nucleogenic nuclides), and others produced as decay products of long-lived primordial nuclides. For example, trace (but detectable) amounts of carbon-14 ($14$C) are continually produced in the air by cosmic rays impacting nitrogen atoms, and argon-40 ($40$Ar) is continually produced by the decay of primordially occurring but unstable potassium-40 ($40$K). Also, three primordially occurring but radioactive actinides, thorium, uranium, and plutonium, decay through a series of recurrently produced but unstable elements such as radium and radon, which are transiently present in any sample of containing these metals. Three other radioactive elements, technetium, promethium, and neptunium, occur only incidentally in natural materials, produced as individual atoms by nuclear fission of the nuclei of various heavy elements or in other rare nuclear processes.

Besides the 94 naturally occurring elements, several artificial elements have been produced by nuclear physics technology. By 2016, these experiments had produced all elements up to atomic number 118.

Abundance
The following graph (note log scale) shows the abundance of elements in our Solar System. The table shows the 12 most common elements in our galaxy (estimated spectroscopically), as measured in parts per million by mass. Nearby galaxies that have evolved along similar lines have a corresponding enrichment of elements heavier than hydrogen and helium. The more distant galaxies are being viewed as they appeared in the past, so their abundances of elements appear closer to the primordial mixture. As physical laws and processes appear common throughout the visible universe, however, scientists expect that these galaxies evolved elements in similar abundance.

The abundance of elements in the Solar System is in keeping with their origin from nucleosynthesis in the Big Bang and a number of progenitor supernova stars. Very abundant hydrogen and helium are products of the Big Bang, but the next three elements are rare since they had little time to form in the Big Bang and are not made in stars (they are, however, produced in small quantities by the breakup of heavier elements in interstellar dust, as a result of impact by cosmic rays). Beginning with carbon, elements are produced in stars by buildup from alpha particles (helium nuclei), resulting in an alternatingly larger abundance of elements with even atomic numbers (these are also more stable). In general, such elements up to iron are made in large stars in the process of becoming supernovas. Iron-56 is particularly common, since it is the most stable nuclide that can easily be made from alpha particles (being a product of decay of radioactive nickel-56, ultimately made from 14 helium nuclei). Elements heavier than iron are made in energy-absorbing processes in large stars, and their abundance in the universe (and on Earth) generally decreases with their atomic number.

The abundance of the chemical elements on Earth varies from air to crust to ocean, and in various types of life. The abundance of elements in Earth's crust differs from that in the Solar System (as seen in the Sun and massive planets like Jupiter) mainly in selective loss of the very lightest elements (hydrogen and helium) and also volatile neon, carbon (as hydrocarbons), nitrogen and sulfur, as a result of solar heating in the early formation of the Solar System. Oxygen, the most abundant Earth element by mass, is retained on Earth by combination with silicon. Aluminium at 8% by mass is more common in the Earth's crust than in the universe and solar system, but the composition of the far more bulky mantle, which has magnesium and iron in place of aluminium (which occurs there only at 2% of mass) more closely mirrors the elemental composition of the solar system, save for the noted loss of volatile elements to space, and loss of iron which has migrated to the Earth's core.

The composition of the human body, by contrast, more closely follows the composition of seawater—save that the human body has additional stores of carbon and nitrogen necessary to form the proteins and nucleic acids, together with phosphorus in the nucleic acids and energy transfer molecule adenosine triphosphate (ATP) that occurs in the cells of all living organisms. Certain kinds of organisms require particular additional elements, for example the magnesium in chlorophyll in green plants, the calcium in mollusc shells, or the iron in the hemoglobin in vertebrates' red blood cells.

Evolving definitions
The concept of an "element" as an indivisible substance has developed through three major historical phases: Classical definitions (such as those of the ancient Greeks), chemical definitions, and atomic definitions.

Classical definitions
Ancient philosophy posited a set of classical elements to explain observed patterns in nature. These elements originally referred to earth, water, air and fire rather than the chemical elements of modern science.

The term 'elements' (stoicheia) was first used by Greek philosopher Plato around 360 BCE in his dialogue Timaeus, which includes a discussion of the composition of inorganic and organic bodies and is a speculative treatise on chemistry. Plato believed the elements introduced a century earlier by Empedocles were composed of small polyhedral forms: tetrahedron (fire), octahedron (air), icosahedron (water), and cube (earth).

Aristotle, c. 350 BCE, also used the term stoicheia and added a fifth element, aether, which formed the heavens. Aristotle defined an element as:

"Element – one of those bodies into which other bodies can decompose, and that itself is not capable of being divided into other."

Robert Boyle

In 1661, in The Sceptical Chymist, Robert Boyle proposed his theory of corpuscularism which favoured the analysis of matter as constituted of irreducible units of matter (atoms); and, choosing to side with neither Aristotle's view of the four elements nor Paracelsus' view of three fundamental elements, left open the question of the number of elements. Boyle argued against a pre-determined number of elements—directly against Paracelsus' three principles (sulfur, mercury, and salt), indirectly against the "Aristotelian" elements (earth, water, air, and fire), for Boyle felt that the arguments against the former were at least as valid against the latter. "Much of what I am to deliver ... may be indifferently apply'd to the four Peripatetick Elements, and the three Chymical Principles ... the Chymical Hypothesis seeming to be much more countenanc'd by Experience then the other, it will be expedient to insist chiefly upon the disproving of that; especially since most of the Arguments that are imploy'd against it, may, by a little variation, be made ... at least as strongly against the less plausible, Aristotelian Doctrine."

Then Boyle stated his own view in four propositions. In the first and second, he suggests that matter consists of particles, but that these particles may be difficult to separate. Boyle used the concept of "corpuscles"—or "atomes", as he also called them—to explain how a limited number of elements could combine into a vast number of compounds.

"Propos. I. ... At the first Production of mixt Bodies, the Universal Matter whereof they ... consisted, was actually divided into little Particles. ... The Generation ... and wasting of Bodies ... and ... the Chymical Resolutions of mixt Bodies, and ... Operations of ... Fires upon them ... manifest their consisting of parts very minute... Epicurus ... as you well know, supposes ... all ... Bodies ... to be produc'd by ... Atomes, moving themselves to and fro ... in the ... Infinite Vacuum. ... Propos. II. ... These minute Particles ... were ... associated into minute ... Clusters ... not easily dissipable into such Particles as compos'd them. ... If we assigne to the Corpuscles, whereof each Element consists, a peculiar size and shape ... such ... Corpuscles may be mingled in such various Proportions, and ... connected so many ... wayes, that an almost incredible number of ... Concretes may be compos'd of them."

Boyle explained that gold reacts with aqua regia, and mercury with nitric acid, sulfuric acid, and sulfur to produce various "compounds", and that they could be recovered from those compounds, just as would be expected of elements. Yet, Boyle did not consider gold, mercury, or lead elements, but rather—together with wine—"perfectly mixt bodies". "Quicksilver ... with Aqua fortis will be brought into a ... white Powder ... with Sulphur it will compose a blood-red ... Cinaber. And yet out of all these exotick Compounds, we may recover the very same running Mercury. ... Propos. III. ... From most of such mixt Bodies ... there may by the Help of the Fire, be actually obtain'd a determinate number (whether Three, Four or Five, or fewer or more) of Substances ... The Chymists are wont to call the Ingredients of mixt Bodies, Principles, as the Aristotelians name them Elements. ... Principles ... as not being compounded of any more primary Bodies: and Elements, in regard that all mix'd Bodies are compounded of them."

Even though Boyle is largely regarded as the first modern chemist, The Sceptical Chymist still contains old ideas about the elements, alien to a modern viewpoint. Sulfur, for example, is not only the familiar yellow non-metal, but also an inflammable "spirit".

Isaac Watts
In 1724, in his book Logick, the English minister and logician Isaac Watts enumerated the elements then recognized by chemists. Watts' list of elements included two of Paracelsus' principles (sulfur and salt) and two classical elements (earth and water) as well as "spirit". Watts did, however, note a lack of consensus among chemists. "Elements are such Substances as cannot be resolved, or reduced, into two or more Substances of different Kinds. ... Followers of Aristotle made Fire, Air, Earth and Water to be the four Elements, of which all earthly Things were compounded; and they suppos'd the Heavens to be a Quintessence, or fifth sort of Body, distinct from all these : But, since experimental Philosophy ... have been better understood, this Doctrine has been abundantly refuted. The Chymists make Spirit, Salt, Sulphur, Water and Earth to be their five Elements, because they can reduce all terrestrial Things to these five :.. tho' they are not all agreed."

Antoine Lavoisier, Jöns Jacob Berzelius, and Dmitri Mendeleev
The first modern list of elements was given in Antoine Lavoisier's 1789 Elements of Chemistry, which contained 33 elements, including light and caloric. By 1818, Jöns Jacob Berzelius had determined atomic weights for 45 of the 49 then-accepted elements. Dmitri Mendeleev had 63 elements in his periodic table of 1869. From Boyle until the early 20th century, an element was defined as a pure substance that cannot be decomposed into any simpler substance. That is, an element cannot be transformed into other elements by chemical processes. Elements at the time were generally distinguished by their atomic weights, a property measurable with fair accuracy by available analytical techniques.

Atomic definitions

The 1913 discovery by English physicist Henry Moseley that the nuclear charge is the physical basis for the atomic number, further refined when the nature of protons and neutrons became appreciated, eventually led to the current definition of an element based on atomic number (number of protons). The use of atomic numbers, rather than atomic weights, to distinguish elements has greater predictive value (since these numbers are integers), and also resolves some ambiguities in the chemistry-based view due to varying properties of isotopes and allotropes within the same element. Currently, IUPAC defines an element to exist if it has isotopes with a lifetime longer than the 10$−14$ seconds it takes the nucleus to form an electronic cloud.

By 1914, eighty-seven elements were known, all naturally occurring (see Discovery of chemical elements). The remaining naturally occurring elements were discovered or isolated in subsequent decades, and various additional elements have also been produced synthetically, with much of that work pioneered by Glenn T. Seaborg. In 1955, element 101 was discovered and named mendelevium in honor of D. I. Mendeleev, the first to arrange the elements in a periodic manner.

Discovery and recognition of various elements
Ten materials familiar to various prehistoric cultures are now known to be elements: Carbon, copper, gold, iron, lead, mercury, silver, sulfur, tin, and zinc. Three additional materials now accepted as elements, arsenic, antimony, and bismuth, were recognized as distinct substances prior to 1500 AD. Phosphorus, cobalt, and platinum were isolated before 1750.

Most of the remaining naturally occurring elements were identified and characterized by 1900, including:
 * Such now-familiar industrial materials as aluminium, silicon, nickel, chromium, magnesium, and tungsten
 * Reactive metals such as lithium, sodium, potassium, and calcium
 * The halogens fluorine, chlorine, bromine, and iodine
 * Gases such as hydrogen, oxygen, nitrogen, helium, argon, and neon
 * Most of the rare-earth elements, including cerium, lanthanum, gadolinium, and neodymium
 * The more common radioactive elements, including uranium, thorium, and radium

Elements isolated or produced since 1900 include:
 * The three remaining undiscovered stable elements: hafnium, lutetium, and rhenium
 * Plutonium, which was first produced synthetically in 1940 by Glenn T. Seaborg, but is now also known from a few long-persisting natural occurrences
 * The three incidentally occurring natural elements (neptunium, promethium, and technetium), which were all first produced synthetically but later discovered in trace amounts in certain geological samples
 * Four scarce decay products of uranium or thorium (astatine, francium, actinium, and protactinium), and
 * All synthetic transuranic elements, beginning with americium and curium

Recently discovered elements
The first transuranium element (element with atomic number greater than 92) discovered was neptunium in 1940. Since 1999, claims for the discovery of new elements have been considered by the IUPAC/IUPAP Joint Working Party. As of January 2016, all 118 elements have been confirmed by IUPAC as being discovered. The discovery of element 112 was acknowledged in 2009, and the name copernicium and chemical symbol Cn were suggested for it. The name and symbol were officially endorsed by IUPAC on 19 February 2010. The heaviest element that is believed to have been synthesized to date is element 118, oganesson, on 9 October 2006, by the Flerov Laboratory of Nuclear Reactions in Dubna, Russia. Tennessine, element 117 was the latest element claimed to be discovered, in 2009. On 28 November 2016, scientists at the IUPAC officially recognized the names for the four newest elements, with atomic numbers 113, 115, 117, and 118.

List of the 118 known chemical elements
The following sortable table shows the 118 known elements.
 * Atomic number, Element, and Symbol all serve independently as unique identifiers.
 * Element names are those accepted by IUPAC.
 * Block indicates the periodic table block for each element: red = s-block, yellow = p-block, blue = d-block, green = f-block.
 * Group and period refer to an element's position in the periodic table. Group numbers here show the currently accepted numbering; for older numberings, see Group (periodic table).

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Chemical element


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Centime

Centime (from centesimus) is French for "cent", and is used in English as the name of the fraction currency in several Francophone countries (including Switzerland, Algeria, Belgium, Morocco and France).

In France, the usage of centime goes back to the introduction of the decimal monetary system under Napoleon. This system aimed at replacing non-decimal fractions of older coins. A five-centime coin was known as a sou, i.e. a solidus or shilling.

In Francophone Canada $1/100$ of a Canadian dollar is officially known as a cent (pronounced /sɛnt/) in both English and French. However, in practice, the form of cenne (pronounced /sɛn/) has completely replaced the official cent. Spoken and written use of the official form cent in Francophone Canada is exceptionally uncommon. In the Canadian French vernacular sou, sou noir (noir means "black" in French), cenne, and cenne noire are all widely known, used, and accepted monikers when referring to either $1/100$ of a Canadian dollar or the 1¢ coin (colloquially known as a "penny" in North American English).

Subdivision of euro: cent or centime?
In the European community, cent is the official name for one hundredth of a euro. However, in French-speaking countries, the word centime is the preferred term. The Superior Council of the French language of Belgium recommended in 2001 the use of centime, since cent is also the French word for "hundred". An analogous decision was published in the Journal officiel in France (2 December 1997).

In Morocco, dirhams are divided into 100 centimes and one may find prices in the country quoted in centimes rather than in dirhams. Sometimes centimes are known as francs or, in former Spanish areas, pesetas.

Usage
A centime is one-hundredth of the following basic monetary units:

Current

 * Algerian dinar
 * Burundian franc
 * CFP franc
 * CFA franc
 * Comorian franc
 * Congolese franc
 * Djiboutian franc
 * Ethiopian birr (as santim)
 * Guinean franc
 * Haitian gourde
 * Moroccan dirham
 * Rwandan franc
 * Swiss franc (by French and English speakers only; Italian speakers use centesimo. See Rappen)

Obsolete

 * Algerian franc
 * Belgian franc (Dutch: centiem)
 * Cambodian franc
 * French Camerounian franc
 * French Guianan franc
 * French franc
 * Guadeloupe franc
 * Katangese franc
 * Latvian lats (Latvian: santīms)
 * Luxembourgish franc
 * Malagasy franc
 * Malian franc
 * Martinique franc
 * Monegasque franc
 * Moroccan franc
 * New Hebrides franc
 * Réunion franc
 * Spanish Peseta
 * Tunisian franc
 * Westphalian frank

title: Centime


text:
Calendar year

Generally speaking, a calendar year begins on the New Year's Day of the given calendar system and ends on the day before the following New Year's Day, and thus consists of a whole number of days. A year can also be measured by starting on any other named day of the calendar, and ending on the day before this named day in the following year. This may be termed a "year's time", but not a "calendar year". To reconcile the calendar year with the astronomical cycle (which has a fractional number of days) certain years contain extra days ("leap days" or "intercalary days"). The Gregorian year, which is in use in most of the world, begins on January 1 and ends on December 31. It has a length of 365 days in an ordinary year, with 8760 hours, 525,600 minutes, or 31,536,000 seconds; but 366 days in a leap year, with 8784 hours, 527,040 minutes, or 31,622,400 seconds. With 97 leap years every 400 years, the year has an average length of 365.2425 days. Other formula-based calendars can have lengths which are further out of step with the solar cycle: for example, the Julian calendar has an average length of 365.25 days, and the Hebrew calendar has an average length of 365.2468 days. The Lunar Hijri calendar is a lunar calendar consisting of 12 months in a year of 354 or 355 days. The astronomer's mean tropical year, which is averaged over equinoxes and solstices, is currently 365.24219 days, slightly shorter than the average length of the year in most calendars.

Quarter year
The calendar year can be divided into four quarters, often abbreviated as Q1, Q2, Q3, and Q4. Since they are three months each, they are also called trimesters. In the Gregorian calendar:

 * 1) First quarter, Q1: January – March (90 days or 91 days in leap years)
 * 2) Second quarter, Q2: April – June (91 days)
 * 3) Third quarter, Q3: July – September (92 days)
 * 4) Fourth quarter, Q4: October – December (92 days)

In some domains, weeks are preferred over months for scheduling and reporting, so they use quarters of exactly 13 weeks each, often following ISO week date conventions. One in five to six years has a 53rd week which is usually appended to the last quarter. It is then 98 days instead of 91 days long, which complicates comparisons.

In the Chinese calendar, the quarters are traditionally associated with the 4 seasons of the year:

 * 1) Spring: 1st to 3rd month
 * 2) Summer: 4th to 6th month
 * 3) Autumn: 7th to 9th month
 * 4) Winter: 10th to 12th month

title: Calendar year