Aarushhh/wikipedia-simple-splitted huggingface dataset:
Calcium is a chemical element. Its symbol on the periodic table (a list of all the elements) is Ca. Its atomic number is 20. (The atomic number says where Calcium sits in the periodic table.) It has 20 protons and 20 electrons (if is an atom, see ion). The most common isotopes are Ca-40 and Ca-44. Its mass number is about 40.08.
Calcium is very important in the human body, for making bones and for other purposes.

Properties

Physical properties 
Calcium is a soft white-gray metal. It is a solid and is opaque. It is an alkaline earth metal.  Its melting point is hotter than most other reactive metals.  It is a little harder than lead. It has two allotropes.  It does not conduct electricity as well as copper, but is much lighter in weight.

Chemical properties
It reacts with water to produce hydrogen and calcium hydroxide. It reacts with water very fast when it is powdered. When it is in a chunk, it starts reacting slowly because calcium hydroxide makes a coating that does not dissolve on the calcium. If a little acid is added to calcium hydroxide, it dissolves it, making the calcium react very fast. It burns when powdered to make a reddish flame. This makes calcium oxide. It also makes calcium nitride when heated. It can react with halogens to make calcium halides like calcium chloride with chlorine.

Calcium compounds
Calcium forms chemical compounds in the +2 oxidation state. Calcium compounds are colorless. Most calcium compounds are not toxic. They are needed in the human body, actually. They are unreactive as far as calcium ions go. Calcium oxide was used to make limelights, which have a flame heating calcium oxide and makes it glow very bright.
Calcium bromate
Calcium carbonate
Calcium chloride
Calcium hydroxide
Calcium nitrate
Calcium nitride
Calcium oxide
Calcium permanganate
Calcium phosphate
Dicalcium phosphate
Monocalcium phosphate

Isotopes
Calcium has 6 naturally occurring isotopes (40Ca, 42Ca, 43Ca, 44Ca, 46Ca and 48Ca), of which 48Ca is very slightly radioactive with a half-life about 6.4×1019 years. Traces of 41Ca, 45Ca and 47Ca are made by cosmic rays striking atoms, and are called cosmogenic nuclides. 41Ca is made by the neutron activation of 40Ca in the upper layers of the Earth's crust and has a half-life of 102,000 years. Since it decays to potassium-41, it is a critical indicator of solar system anomalies.

Calcium-40 is the most abundant isotope (96% of all natural calcium), since it comes from radiogenic 40K, which has a half-life of 1.25 billion years. However, along with calcium-46, it is theoretically unstable but with a half-life so long it has never been observed to decay.

Occurrence

In the ground
In the ground

Calcium is not found as a metal in the ground; it is too reactive. Calcium carbonate, also known as calcite, is the most common calcium mineral.

Calcium in cells 
It is important to know how cells work. Many cells have calcium channels on their surface. These are openings where calcium ions can enter the cell. The cell is told to act and it opens the channels. Once in the cell calcium ions activates many proteins to do specific things. For example, when it goes into muscle cells, it makes them contract (shorten so the muscle pulls.) When it goes into nerve cells, it triggers electrical impulses that send a message. When it goes into white blood cells, it makes them fight germs.

Calcium ions are important to cells, but too many calcium ions can be bad. If a cell gets more calcium ion than it needs, it can die. This is why the amount of calcium ion in cells is highly regulated. Conversely, not enough calcium ion is bad. Cells must have the right amount to function properly.
Sometimes cells are unhealthy and need to die in for the body to replace them with new, healthy cells. This keeps the whole organism healthy. Cells know when they should die and can trigger reactions to end their life cycles in many ways. When this happens it is called apoptosis, also known as a 'programmed cell death' (planned cell death.) One way cells accomplish apoptosis by taking in toxic levels of calcium ions.

Calcium is very important for the human body.

Calcium storage 
Bones contain most of the calcium ion in the human body. If we need more calcium for our blood, muscles, or other tissue, it comes from the bones. If we have extra calcium it goes into bones.

Calcium as an element is not found in the human body, just calcium ions in the form of chemical compounds.

Calcium regulation 
Organisms need to keep calcium ion levels very well controlled. High calcium levels are bad, and low calcium levels are bad.
The body controls this by changing
 how much calcium we get from the food we eat
 how much calcium we lose in urine
 how much calcium is put in bones
The control of calcium in the body is called calcium metabolism. Too little calcium can cause osteoporosis.

The body controls calcium levels with many hormones. Calcitonin, Parathyroid hormone (acronym PTH), and Vitamin D are the most important hormones in calcium metabolism. (Vitamin D works as a hormone but it is called a vitamin.)

Preparation
Calcium metal is made by electrolysis of melted calcium chloride. It has to be very hot to melt it. The calcium metal is liquid.

Uses

As an element
Calcium is used in the reduction of other metals. It can also be used to make alloys with other metals.

As chemical compounds

Calcium compounds are also important in chemistry. It is important for making things. It is a part of cement which is needed to make concrete (a hard substance that many buildings are made from.)
Calcium is part of calcium oxide. Calcium oxide is used to make paper, pottery, food, and to purify water (make it good to drink.) Calcium carbonate is used as a calcium supplement. Calcium permanganate can be used as a rocket propellant.

Safety 
Calcium is toxic as an element. It reacts with water and makes a strong base, calcium hydroxide. Calcium compounds are not toxic unless the anion is toxic. Calcium permanganate is only toxic because of the permanganate, not the calcium.  Like other alkaline earth metals calcium burns easily and brightly.

Related pages
Calcium compounds

Sources

Other websites 
 Calcium -Citizendium

Alkaline earth metals
A Series of Unfortunate Events is a series of 13 books written for children by the author Lemony Snicket. They tell the story of three unlucky orphans (Violet Baudelaire, Klaus Baudelaire, and Sunny Baudelaire) and their lives after the death of their parents. The main villain of the books is Count Olaf who wants to steal Baudelaires' inheritance (the money their parents left behind). Count Olaf uses many disguises to get their fortune.

In other media
In 2004, there was a movie version, "Lemony Snicket's A Series of Unfortunate Events," from Paramount Pictures and Nickelodeon movies, starring Jim Carrey as Count Olaf.

In 2012, a new series from Lemony Snicket named All the Wrong Questions was written. The series tells the story of Lemony Snicket, a member of a group named V.F.D which is an important part of the series, when he was a child.

In 2016, the series was broadcast through Netflix (children's section).

Other websites 

Lemony Snicket's website
American children's books
2004 movies
Paramount Pictures movies
Black comedy
A membrane is a thin soft layer of material. A membrane separates two things.

In biology a membrane can mean two things: a tissue membrane or the membranes of a cell. The membranes of cells are very small, while tissue membranes are larger.

Tissue membranes
A membrane can mean a thin layer of cells or tissue. This layer covers the body or an organ, or separates, or lines a body cavity. An example is the mucous membrane that is the skin that lines the inside of your nose and mouth. An epithelial membrane has two parts, one part is epithelial tissue and the other is connective tissue.

Membranes of cells

There are many different types of membranes in a cell. The cell membrane, also called the plasma membrane, covers one cell. Membranes also divide the cell into different spaces called organelles. Organelles are special areas of the cell that do different work. For example, the nucleus holds the DNA in a cell. The mitochondria make energy for the cell.
Membranes in cells are made of lipids (fats) and protein. The lipids keep the inside of the cell or the organelle separate from the outside. The proteins do many things. Plasma membranes give the cell messages from outside. They let some things (like glucose, calcium, and potassium) go into and out of the cell.

Cell biology
Plant anatomy
François-Marie Arouet (also known as Voltaire) was a French philosopher. He was born in 1694 and grew up in Poitou. He died in Paris in 1778.

Voltaire did not like France at the time because he thought that it was old fashioned. He also did not like the Church and thought that people should be allowed to believe what they want. However he did not like democracy either and thought that a country needed to be led by a wise and strong king. Voltaire had to live in exile in England for three years from 1726 to 1729 where these ideas were more common. He liked the philosophy of John Locke.
Voltaire was also a writer. He wrote many books, poems and plays, some of which are still liked today. A lot of his work was against France and the Church. This meant that he was unpopular at first but became more popular towards the time of the French Revolution. He also studied science and wrote a lot about people and places he knew. His writings later led to the French revolution, which changed France from a Hereditary Monarchy into a Republic. 

Voltaire believed in a God but did not believe in a God personally involved in people's lives, like the Christian God. This is called Deism.

Note

Other websites 

 An analysis of Voltaire's texts (in the "textes" topic) (in French)
 
 Voltaire's writings from Philosophical Dictionary
 Société Voltaire
 Voltaire's Candide and Leibniz 
 VisitVoltaire.com 
  Voltaire, his work in audio version  

1694 births
1778 deaths
17th-century philosophers
French deists
French philosophers
Pen names
Missouri is one of the 50 states in the United States. Its capital is Jefferson City. Its largest cities are Kansas City and Saint Louis.  Some other cities are Columbia (which is where the University of Missouri is), and Springfield.

Missouri officially became a state on August 10, 1821.

Missouri's edges touch a total of eight states: Iowa lies to the north; to the east, across the Mississippi River, are Illinois, Kentucky, and Tennessee; Arkansas lies to the south; and on the west are Oklahoma, Kansas, and Nebraska (Kansas and Nebraska are across the Missouri River).

History
Native Americans first settled in Missouri before the arrival of Europeans.

Related pages
 List of counties in Missouri

References

Other websites

 
 
 Missouri State Guide, from the Library of Congress
 
 
 
 
 
 
 
 

 
1821 establishments in the United States
South Dakota is a state in the United States. South Dakota became a state on November 2, 1889. Its capital is Pierre and largest city is Sioux Falls. Other important cities are Rapid City and Aberdeen.  Famous attractions include Mount Rushmore, the Black Hills, and the Wall Drug Store.  The Corn Palace is also famous, and it is in Mitchell. About 890,000 people lived there in 2020.

South Dakota is bordered to the north by North Dakota, to the south by Nebraska, to the east by Iowa and Minnesota, and to the west by Wyoming and Montana.

There are nine Native American tribes that live in South Dakota.

Related pages
 Colleges and universities in South Dakota
 List of counties in South Dakota

References

Other websites 

 The Official Home Page of South Dakota 

 
1889 establishments in the United States
People are known to have lived in Wimbledon since the Iron Age when the hill fort on Wimbledon Common was built. At the time the Domesday Book was written (about 1087), Wimbledon belonged to the lord of the manor of Mortlake. The ownership of the manor of Wimbledon changed between various rich families many times during its history, and the area also attracted other wealthy families who built large houses such as Eagle House, Wimbledon House and Warren House. The people in the village were either poor people who worked on the land or they were rich and important people. The rich and poor people lived together happily. In the 18th century the Dog and Fox public house became a stop on the stagecoach run from London to Portsmouth, then in 1838 the London and South Western Railway (L&SWR) opened a station to the south east of the village at the bottom of Wimbledon hill. After the station was built, new houses were built near to it, and many people began living near the station
. In the second half of the 19th century the number of people living in Wimbledon grew quickly. At the start of the 19th century there were about 1,000 people living in Wimbledon; then in 1911 there were about 55,000 people. During this time large numbers of villas and terraced houses were built out along the roads from the centre towards neighbouring Putney, Merton Park and Raynes Park.
Geography

Wimbledon lies in the south west area of London, south of Wandsworth, and east of Kingston upon Thames on the outskirts of Greater London. It is  south-west of the centre of London at Charing Cross. It is considered an rich suburb with a mix of grand Victorian houses, modern housing and low rise apartments. The residential area is split into two sections known as the village and the town, with the village around the High Street being part of the original medieval village, and now a prime residential area of London commanding high prices,  and the "town" being part of the modern development since the building of the railway station in 1838.

The area is identified in the London Plan as one of 35 major centres in Greater London.

The population consists around 57,000 adults, the majority in the ABC1 social group. The population grew from around 1,000 at the start of the 19th century to around 55,000 in 1911, a figure which has remained reasonably stable since.
Governance
Originally Wimbledon had its own borough of Wimbledon and was within the county of Surrey; it was absorbed into the London Borough of Merton as part of the creation of Greater London in 1965. It is in the Parliamentary constituency of Wimbledon, and since 2005 it has been represented by Conservative MP Stephen Hammond.

Wimbledon Football Club

Wimbledon Football Club was began in Wimbledon in 1889.  In 2002 it moved to Milton Keynes and it 2004 it changed its name to Milton Keynes Dons F.C.  Many football fans in Wimbledon did not agree with the move.  They decided to start a new club there, which is called AFC Wimbledon.

The club played in the English Football League and won the FA Cup in 1988.  It was a professional football club, which means that the players get paid to play.

References

Other websites
Other websites

Local authorities
merton.gov.uk
Community
wimbledon-village.com
History
british-history.ac.uk  The Environs of London: Volume 1: County of Surrey, 1792, "Wimbledon", pp. 519–540, Daniel Lysons
british-history.ac.uk   A History of the County of Surrey: Volume 4, 1912, "Parishes: Wimbledon",  pp. 120–125, H.E. Malden (editor)

London Borough of Merton
The Mersey Beat or Mersey Sound or Liverpool Sound is the name for a type of music that came out in the city of Liverpool, England in the early 1960s. 

Maybe the first group to be thought of as a part of genre were Kingsize Taylor and the Dominoes. The most famous group of this genre were The Beatles. Other important groups include Gerry and the Pacemakers, The Searchers and the female singer Cilla Black.

Other websites 
http://www.merseybeat.co.uk/ 
http://www.merseybeatnostalgia.co.uk/ 
http://www.merseybeatabd.co.uk/ 
Newsreel footage of The Fourmost 
Short news story on Mersey Sound 

Music genres
Musical groups from Liverpool
Year 1078 (MLXXVIII) was a common year starting on Monday of the Julian calendar.

Events 
 The Tower of London is built.
 Philaretos Brachamios does not keep his claim to the Byzantine Empire after he becomes duke of Antioch.
 August 7 – Battle of Mellrichstadt between Henry IV, Holy Roman Emperor and the German anti-king Rudolf of Swabia

Births 
 King Alexander I of Scotland, Scottish royal (died 1124)
 Constance of France, daughter of King Philip I of France (died 1118)
Events 
 March 18 – Britain repeals the Stamp Act after American protests.

Births
 February 14 – Thomas Malthus, English demographer and economist (died 1834)
 April 6 – Charles Louis de Fourcroy, Chevalier de la Légion d'honneur, French Mathematician and Scholar
 April 22 – Anne Louise Germaine de Stael, French writer (died 1817)
 May 30 – Robert Darwin, Medical doctor and father of Charles Darwin (died 1848)
 July 8 – Dominique Jean Larrey, French surgeon (died 1842)
 August 6 – William Hyde Wollaston, English chemist (died 1828)
 September 6 – John Dalton, English chemist and physicist (died 1844)
 October 23 – Emmanuel, marquis de Grouchy, French marshal (died 1847)
 November 2 – Joseph Radetzky von Radetz, Austrian field marshal (died 1858)
 December 3 – Barbara Fritchie, U.S. patriot in Civil War (died 1862)

Deaths
The Adventures of Pete and Pete was an American television show on the Nickelodeon network in the early 1990s. It was about two brothers with the same first name who grow up together.

Other websites 
  The Website of Pete and Pete

Comedy television series
Nickelodeon television series
1993 American television series debuts
1996 American television series endings
1990s television series
American comedy television series
American comedy-drama television series
American drama television series
English-language television programs
Year 427 BC was a year of the pre-Julian Roman calendar.

Events 
 Sparta's King Archidamus II is succeeded by his son Agis II.
 Cleon says Mytilene must be destroyed. He decides not to kill the people.
 Plataea surrenders to the Spartans and Thebans. Over 200 prisoners are put to death and Plataea is destroyed.
 The civil war in Corcyra results in a victory of the democrats over the oligarchs.
 The Quaestorship is opened to the Plebs.

Births 

 Plato, Greek philosopher (d. c. 347 BC)
 Xenophon, Greek historian, soldier, mercenary and an admirer of Socrates (d. 354 BC)

Deaths 

 Archidamus II, king of Sparta
A motorcycle (or motorbike) is a vehicle used to transport people from one place to another. It does not have 4 wheels like a car. It has 2 wheels like a bicycle, and it has a motor like a car. A motorcycle is usually driven by one person. A passenger can also ride on the back of the motorcycle. Some motorcycles have a sidecar that can carry another passenger.

In 1901, the first successful motorcycle was made by the company called "Indian motorcycles" in Springfield, Massachusetts. Since then, many other companies have made them.  Major manufacturers include Honda, Suzuki, Yamaha. A well known American manufacturer of motorcycles is Harley-Davidson.
Since motorcycles are lighter than almost all cars, they can accelerate more quickly. But it also makes them not as safe as cars, because they do not have a protecting chassis around them like cars. Very often motorcycle riders are injured heavily in accidents. Motorcycle riders should wear a helmet and other protective clothing like shoes and gloves, of which some have armor. This special clothing may reduce the rider's injuries in an accident. Motorcycles also do not protect riders against wind and rain. That makes it difficult to drive in winter or during bad weather.

In poor countries, motorcycles are used by many as a cheap method of transportation. Many people who do not have the money to buy a car can afford a small motorcycle. In rich countries, large powerful motorcycles are used more as a hobby or sport.

Off road
Off road 

On-road bikes (ones that are allowed on public roads) require the rider to have a special type of driver's license to be ridden legally. Off-road bikes are not allowed to be driven on public roads.

Speed and stunts are the main goals for off-road bike sports. Many on-road bikes are much faster than off-road bikes and can be used in sports such as motorbike racing.

Motocross is a form of motorcycle racing.  It is on an off-road circuit. The sport came from motorcycle trials competitions held in the United Kingdom.

References

 
Springfield, Massachusetts
1585 was a common year.

Births 
 December 4 – John Cotton, American Puritan leader
Guinea pigs (Cavia porcellus) are a kind of rodent. They are not pigs and are not from Guinea. The reason for why this is the name is unclear. They are also called cavies. They are domesticated animals which originated in the Andes. 

Studies on biochemistry and hybridization suggest they are descendants of a closely related species of cavy. They do not occur naturally in the wild.

Guinea pigs as pets 
In many parts of the world, people keep them as pets. In Peru, Bolivia, and several other countries, they are raised for food. The first people who domesticated the animals, did it for food. Besides being a pet and a source of food, in some places people think guinea pigs keep bad spirits away. In Quechua, the language of some the native tribes of Peru, they are called . The Spanish-speaking people of the region call them cuy (plural: cuyes).
Name
This perception of pigginess occurred in many languages other than English; the German word for them is Meerschweinchen, literally "little sea pigs" (sailing ships stopping to reprovision in the New World would pick up stores of guinea pigs, which provided an easily transportable source of fresh meat), the Russian and Polish word for them is similar, "morskaya svinka" (Морская свинка) and "świnka morska" respectively, meaning also "little sea pig" (it comes from archaic use of the word to mean "overseas"). However, this perception of pigginess is not universal to all languages or cultures. For example, the common Spanish term is 'conejillo de Indias' (Indian bunny rabbit).
Housing and breeding guinea pigs 
Guinea pigs need large open air cages in which to romp and frolic. They should have a diet of 1/8 cup of high quality grass-based guinea-pig pellets daily, as per manufacturer’s instructions. They should also have unlimited grass hay, and at least one cup of a variety of veggies. Guinea pigs like to be held in hand.
Guinea pigs should be kept in cages larger than 7.5 square feet or 10.5 square feet for 2 pigs. They should always have a friend as guinea pigs are social animals.
Breeding guinea pigs are not recommended as the rate of pregnancy complications is high.

For their diet guinea pigs generally prefer hay, fresh fruits and vegetables.

Other uses of the term 
Guinea pig is also slang for a person who is the first to try something. It can also mean the subject of an experiment. This is because guinea pigs are used by biologists as model organisms.

References

rodents
pets
Domesticated animals
Mammals of South America
Events 
 The Spanish arrive in Peru.
 Death of Protestant reformer Huldrych Zwingli
Philip Morris Glass (born January 31, 1937) is an American composer of modern music. He is one of the most influential music makers of the late 20th century.

Glass has created operas, music for quartets, dance, and much more. He is known for writing minimalist music.

Glass has described himself instead as a composer of "music with repetitive structures". Though his early music shares much with what is called "minimalist", he has since evolved stylistically.

References

Other websites 
 Official website

1937 births
Living people
21st-century American composers
20th-century American composers
Audioslave is an American rock band. The band is made up of Chris Cornell (vocals), who was with Soundgarden until 1997, and Tom Morello (guitar), Tim Commerford (electric bass) and Brad Wilk (drums), who were with Rage Against The Machine until 2000.

Their first album Audioslave was released in 2002 and the next one, named Out of Exile, followed in 2005. On May 6, 2005 Audioslave became the first American rock group to play in Cuba. Because of American laws against trade with Cuba, this concert had to be allowed by US authorities.

Studio albums 
 Audioslave (2002)
 Out of Exile (2005)
 Revelations (2006)

Other websites
Official website

2000s American music groups
American rock bands
American hard rock bands
Post-grunge bands
Musical groups from Los Angeles
Musical groups established in 2001
2001 establishments in California
Musical groups disestablished in 2007
2007 disestablishments in the United States
2000s disestablishments in California
Environment means what surrounds us. It may be living or non-living things. It includes physical, chemical and other natural forces. Living things live in their environment. They constantly interact with it and adapt themselves to conditions in their environment. In the environment there are different interactions between animals, plants, soil, water, and other living and non-living things.

The word environment is used to talk about many things. People in different fields of knowledge use the word environment differently. Electromagnetic environment is radio waves and other electromagnetic radiation and magnetic fields. The environment of a galaxy may mean the interstellar medium, or it may mean other nearby galaxies.

In psychology and medicine, a person's environment is the people, physical things and places that the person lives with. The environment affects the growth and development of the person. It may affect the person's behavior, body and mind.
The conditions of living organisms in an environment are affected by the weather and climate changes in the environment. They are also greatly affected by other living things.

Natural environment

In biology and ecology, the environment is all of the natural materials and living things, If those things are natural, it is a natural environment.

Environment includes the living and non-living things that an organism interacts with, or has an effect on it. Living elements that an organism interacts with are known as biotic elements: animals, plants, etc. Abiotic elements are non living things which include air, water, sunlight etc. Studying the environment means studying the relationships among these various things. An example of interactions between non-living and living things is plants getting their minerals from the soil and making food using sunlight. Predation, an organism eating another, is an example of interaction between living things.
Environmentalists think we should protect the natural environment, to keep it safe. Things in the natural environment that we value are called natural resources. For example; fish, insects, and forests. These are renewable resources because they come back naturally when we use them. Non-renewable resources are important things in the environment that are limited for example, ores and fossil fuels after a few thousand years. Some things in the natural environment can kill people, such as lightning.

 Ecological units which are natural systems without much human interference. These include all vegetation, microorganisms, soil, rocks, atmosphere, and natural events.
 Universal natural resources and physical phenomenon which lack clear-cut boundaries. These include climate, air, water, energy, radiation, electric charge, and magnetism.

Related pages
Environmental chemistry
Environmental factor
Environmental revitalization
Environmentalism
Ecology
A tooth is one of the hard, white things in the mouth. Teeth (plural) are used to help the mastication process by chewing food. Chew means to break up and crush food so it can be swallowed (pushed down into the stomach). 

Most vertebrates have teeth. Birds are the biggest group that do not. Many invertebrates have mouthparts which, to some extent, act like teeth. Different animals have different kinds of teeth because they eat different foods. Some animals use teeth as a weapon. Human adults usually have 32 teeth. Human children usually have 20 teeth.

Natal teeth 
Some human babies are born with teeth. Natal teeth are teeth that are present at birth. These are different from neonatal teeth which are teeth that emerge during the first month of life. Natal teeth are not common. They occur in about 1 out of every 2–3 thousand births. They are usually found on the lower jaw. Natal teeth are usually not well attached and may easily wobble.
Teeth eruption 
Deciduous teeth or milk teeth or temporary teeth are the first set of teeth for most mammals.  Humans have 20 of them. The first teeth (called "primary teeth") start to erupt (come through the gums of the jaw) when a baby is about 6 months old. When these teeth erupt it can really hurt. Babies chew on things to make the pain better. This is called teething (verb: to teethe). Most children have all 20 teeth by two or three years of age. 

At age 6–7 the permanent teeth start to erupt. By the age of 11–12 most children have 28 adult teeth. The last four teeth, called 'wisdom teeth' or third molars come in by age 17–21 in most people. Some people never grow wisdom teeth. Or they may have only two instead of four.

Teeth structure
Teeth structure 

The outside white part of teeth is called the enamel. The enamel is made of calcium phosphate and is very hard. Under the enamel is the dentine. The dentine is softer than the hard enamel. So it is hurt more by tooth decay (cavities). Under the dentine is the pulp which has the nerves and blood vessels that go to the tooth. This is the part that causes the pain of a toothache. Cementum is outside the dentine where there is no enamel. Cementum holds the tooth to the bone of the jaw.

Types of teeth 
 Incisor
 Canine tooth
 Premolar
 Molar

Healthy teeth 
If they are protected and kept clean, teeth should stay for a person's whole life. Many people lose their teeth early because they do not do the right things to keep teeth healthy.
Some things people can do to keep teeth healthy:
 Brush teeth after every meal and at bedtime with a soft-bristled brush.
 Floss after every meal (but at least once a day at bedtime). Flossing should be done before brushing!
 Drink water with fluoride before brushing. Or, use a fluoride mouthrinse (but not for children under age 6).
 See a dentist every 6 months for a tooth exam and tooth cleaning.
 Eat a healthy diet.
 Sugars like sucrose and glucose are bad for teeth.
 Milk and cheese are good for teeth because they have calcium.
 However, milk contains lactose which can cause cavities. Due to this, drinking a lot of milk can still cause cavities.
 Unsweetened (no sugar) chewing gum helps clean teeth, and makes salvia and removes food particles.
 Nothing with flavor in-between meals, give your saliva the two to three hours it needs to clean teeth. The saliva can not do that if there is a continuous food film being put on to the teeth.
Dehydration leads to less saliva production. Drink plenty of water every day.
Disease of teeth 
Plaque is the soft white substance that forms on teeth when they are not cleaned. It has bacteria in it that hurt enamel. If plaque is not cleaned off, after 2 days it can become tartar. Tartar is a hard substance that forms on teeth (mostly near the gums).  Tartar makes gums unhealthy and makes more bacteria grow on the teeth.

Plaque is cleaned off with a toothbrush. If tartar forms on teeth, a dentist must clean it off. 

The bacteria that are on teeth eat into the enamel. Cleaning and flossing teeth, eating good foods, and having a dentist take off plaque make less bacteria on teeth. If there is too much bacteria, they eat enamel faster than teeth make enamel. This makes holes in enamel called cavities. When a person gets cavities, he has the disease dental caries. Making cavities in enamel happens slowly. But once cavities go through enamel, the soft dentine is hurt much faster. Cavities may be fixed by dentists.

Related pages 
 Dental formula
 Dentition
 Dentures

References
References

Other websites 

 The New Student's Reference Work Wikisource
 Tooth Citizendium

Basic English 850 words
Petula Clark, CBE (born 15 November 1932) is a British singer, actress and composer. She was born in Epsom, Surrey. She began her career as a child and was popular in Britain during World War II. In the 1950s, she became a successful pop singer, first in the UK, then in continental Europe, and finally in the United States in the mid-1960s. Her most famous song is "Downtown," which was recorded in four languages and sold nearly five million copies worldwide. Her films include The Card (1952), The Runaway Bus (1956), Finian's Rainbow (1968), and Goodbye, Mr. Chips. She continues to record and perform in concert.

Other websites 

Actors from Surrey
British child actors
British child singers
English movie actors
English pop singers
English television actors
Singers from Surrey
1932 births
Living people
Warner Bros. Records artists
Sir Thomas John Woodward  (born 7 June 1940), known professionally as Tom Jones, is a Welsh singer. He has won Grammy Awards. Jones is particularly noted for his powerful voice. He released his first album Along Came Jones in 1965. He has released thirty-nine studio albums since then. He released his most recent album Spirit in the Room in 2012.

Early life
He was born at 57, Kingsland Terrace, Treforest, Pontypridd, South Wales.

Personal life
Jones was married to Linda from 1957 until she died of cancer in 2016. He has a son (born 1957) by Linda. He has a son (born 1988) by another woman.

Other websites

References 

1940 births
Living people
Brit Award winners
British R&B musicians
British soul musicians
Grammy Award winners
Musicians from Glamorgan
Officers of the Order of the British Empire
Welsh pop singers
Knights Bachelor
Interscope Records artists
Slade is an English Hard rock /Glam rock band. The band started in 1966 and were popular in the 1970s and 1980s. The band released fifteen studio albums and four live albums. 

With worldwide success, particularly in the UK and Europe, the band scored six number one singles on the UK chart, and a total of 24 top forty singles in the country. The original line-up split in 1992 which led guitarist Dave Hill and drummer Don Powell to form Slade II, with new members. The new line-up continues to tour today.

In 1975, the band made a film titled Slade in Flame.

Members
 Noddy Holder - Vocals / guitars / bass guitar
 Dave Hill - Guitars / vocals / bass guitar
 Jim Lea - Bass guitar / vocals / keyboards / violin / guitars
 Don Powell - Drums / percussion
Albums
 Beginnings (as Ambrose Slade, 1969)
 Play It Loud (1970)
 Slade Alive! (1972)
 Slayed? (1972)
 Sladest (1973)
 Old New Borrowed and Blue (1974)
 Slade in Flame (1974)
 Nobody's Fools (1976)
 Whatever Happened to Slade (1977)
 Slade Alive Vol. 2 (1978)
 Return to Base (1979)
 We'll Bring the House Down (1981)
 Till Deaf Do Us Part (1981)
 Slade on Stage (1982)
 The Amazing Kamikaze Syndrome (1983)
 Keep Your Hands Off My Power Supply (1984)
 Rogues Gallery (1985)
 Crackers – The Christmas Party Album (1985)
 You Boyz Make Big Noize (1987)
 Wall of Hits (1991)
 Keep on Rockin''' (1994) (as Slade II)
 Cum On Let's Party (2000) (as Slade II'')

English rock bands
Events 
 July 4 – the United States of America say that they are no longer part of England (the Declaration of Independence)
 July 12 – Captain James Cook starts his third, and final, voyage to the Pacific Ocean
 The city of San Francisco is founded in California, USA (San Francisco was then part of Spain).
 The Wealth of Nations by Adam Smith is published. It is an important book in the history of economics.

Births 
 January 24 – E.T.A. Hoffmann, German writer, composer, and painter (died 1822)
 February 11 – Joannis Capodistrias, Greek governor of Troezen (died 1831)
 March 10 – Louise of Mecklenburg-Strelitz, Queen of Prussia (died 1810)
 April 1 – Sophie Germain, French mathematician (died 1831)
 June 11 – John Constable, English painter (died 1837)
 August 9 – Amedeo Avogadro, Italian chemist (died 1856)
 Muttusvami Dikshitar, Indian composer

Deaths 
 August 25 – David Hume, Scotish philosopher
Deep Purple are a rock band started in Hertford, England, in 1968. Their best known song is "Smoke on the water" from the album "Machine Head". Some of their other albums like  "Deep Purple in Rock" where a great hit and was rated #1 in Germany. Deep Purple are one of the pioneering bands and founders of the hard rock and heavy metal genre.

History
History

Forming, and Mark I (1967–1969)
In 1967, a drummer called Chris Curtis was putting a new band together, where members would only be part of it when it suited them (or would "get on and off"). Because of this format, the band was called Roundabout. The first musicians to be hired were guitar player Ritchie Blackmore and keyboard player Jon Lord. Curtis behaved in a disorderly way, and so was fired from his own project. Blackmore and Lord wanted to continue, and so finished putting the band together themselves, with singer Rod Evans, bass player Nick Simper, and drummer Ian Paice. They renamed the band "Deep Purple" after a song Blackmore's mother liked, disliking the name "Roundabout".
Mark II and success (1969–1973)
The band found a new singer called Ian Gillan and a new bass player called Roger Glover, forming Mark II. Jon Lord used to play in orchestras, and at this time, wanted to go back to them and base the Deep Purple sound around that. Whilst the band did perform as an orchestra (with new singer Ian Gillan writing lyrics) gaining the band some publicity, Gillan and Blackmore were not happy about the band being associated with orchestras, and were firm about Deep Purple being a hard rock band, though Jon Lord would write another orchestral piece for the band.
The band followed "In Rock" up with "Fireball" in 1971, which did show hints of creative progressive rock but was still as heavy as the last album. Just weeks later, the band started working on the next album, which would become "Machine Head". An incident at a Frank Zappa & the Mothers of Invention concert would inspire the band to write their most popular song, "Smoke on the Water" which ended up on the album. "Machine Head", released in 1972, was another success and featured several other popular songs like "Highway Star" and "Space Truckin'".

Mark II's last album was "Who Do We Think We Are" in 1973, and it featured another hit song for the band, "Woman from Tokyo". Ian Gillan left the band that year as he did not like the band's touring and recording schedule, because at the time he wanted a break. He was also arguing with Ritchie Blackmore. Roger Glover left shortly after, also because of arguing with Blackmore.
Marks III and IV (1973–1976)
David Coverdale and Glenn Hughes were hired to replace Ian Gillan and Roger Glover. Glenn Hughes also had singing talent so it was decided he would act as lead singer on some of the band's songs too. In fact, since Hughes was hired first, the band considered performing as a 4-piece from then on, with Hughes singing full-time as well as playing bass.

Mark III's first album, "Burn", released in 1974, was successful and seemed to point a positive picture for the band's future without Gillan or Glover. The singing harmonies from Coverdale and Hughes had something of a blues and funk style to them. These styles were explored more on the band's next album, "Stormbringer", released later the same year. Ritchie Blackmore left after he became more unhappy with this style of music, feeling it was just "shoeshine music".
Although many fans were wondering if Deep Purple could carry on without Blackmore, who had been their highly regarded guitar player from their formation up until this point, they chose to continue, and hired American guitar player Tommy Bolin (forming mark IV). The next album, "Come Taste The Band", showed Bolin bringing a further funk influence into the band's music, having a more creative output than Blackmore did when he left the band.

Breakup, and other projects (1976–1984)
Ian Paice and Jon Lord, the last remaining founding members, agreed to end Deep Purple in 1976 after touring was over, but did not inform any other members. Shortly after, Coverdale informed them he was leaving the band, and only then did Jon Lord tell him: "David, there's no band to leave!" Glenn Hughes and Tommy Bolin were excited about the next Deep Purple album before they too were told that Paice and Lord had ended the band.
David Coverdale started a band of his own called Whitesnake, and Ian Paice and Jon Lord were members for a period of time. Ian Gillan had been performing in a solo band since he left in 1973. Ritchie Blackmore had started a band called Rainbow after leaving in 1975, releasing some successful albums with Ronnie James Dio as lead singer, who would carry on his fame in Black Sabbath and Dio (his own solo band). However, Tommy Bolin would only release one more solo album before he died in 1976, due to drug use.

Rod Evans put together a band and tried to perform as "Deep Purple", advertising it as a reunion although he was the only member who had ever been part of the band during its initial time together. Legal action was taken against him by the real representatives of Deep Purple, who sued him for using the band name without permission.
Mark II reformations and Marks V and VI (1984–1994)
A real Deep Purple reunion happened in 1984 when the Mark II lineup got back together, and released the album "Perfect Strangers" that same year. It sold very well and was well received from fans who were excited about the return of the band's iconic lineup. The songs "Knockin' At Your Back Door" and "Perfect Strangers" were popular. The band also enjoyed success on tour.
Revival with Steve Morse and Jon Lord's retirement (Marks VII and VIII) (1994–present)
With Steve Morse in the band, Deep Purple enjoyed renewed success on tour. Ian Gillan was especially pleased that Ritchie Blackmore was no longer in the band, as he felt his departure saved them from a breakup. Since 1994, Deep Purple have enjoyed more success touring than with their studio albums, although their material written with Morse has received good reviews, with fans and critics feeling the band has more creativity again. Mark VII released two albums, "Purpendicular" (1996) and "Abandon" (1998), before Jon Lord retired in 2002, feeling the need to step down from the band's hard touring schedule. He was replaced by Don Airey.
Over the next few years, Deep Purple released two more albums, "Bananas" (2003) and "Rapture of the Deep" (2005). Their next tour, the "Rapture of the Deep tour" started in 2006, and finished in 2011, making it their longest tour to date. In 2012, Jon Lord died after battling cancer at the age of 71. The band continue to record as well as tour, and released their nineteenth and latest album, "Now What?!", in 2013.

Band members

Current
 Ian Gillan - Vocals (1969–1973, 1984–1989, 1992–present)
 Steve Morse - Guitar (1994–present)
 Roger Glover - Bass (1969–1973, 1984–present)
 Ian Paice - Drums (1968–1976, 1984–present)
 Don Airey - Keyboards, organ (2002–present)
Former
 Ritchie Blackmore - Guitar (1968–1975, 1984–1993)
 Jon Lord - Keyboards, organ, vocals (1968–1976, 1984–2002)
 David Coverdale - Vocals (1973–1976)
 Glenn Hughes - Bass, vocals (1973–1976)
 Rod Evans - Vocals (1968–1969)
 Tommy Bolin - Guitar, vocals (1975–1976)
 Joe Lynn Turner - Vocals (1989–1992)
 Joe Satriani - Guitar
 Nick Simper - Bass, vocals

Lineups
Ian Paice is the only member to be in all of the band's lineups.

Mark I (1) (1968–1969):

The first complete lineup of the band. They released a single that was fairly successful in America called "Hush". Rod Evans and Nick Simper were fired as the other members wanted to play heavier rock music and did not think they would play this style of music well.

 Lead singer - Rod Evans
 Guitar player - Ritchie Blackmore
 Bass player - Nick Simper
 Drummer - Ian Paice
 Keyboard player - Jon Lord

Mark II (2) (1969–1973, 1984–1989, 1992–1993):
This is the band's most famous lineup, releasing albums such as "Deep Purple in Rock" and songs such as "Smoke on the Water". In 1973, Ian Gillan left the band as he did not like the band's touring and recording schedule, because at the time he wanted a break. He was also arguing with Ritchie Blackmore. Roger Glover left shortly after, also because of arguing with Blackmore.

In 1984, this lineup of the band got back together. However, Ian and Ritchie started arguing again over the future of the band, meaning Gillan was fired in 1989. He rejoined in 1992, bringing this band lineup together for the third time, although Blackmore left a year later, this time, for good.

 Lead singer - Ian Gillan
 Guitar player - Ritchie Blackmore
 Bass player - Roger Glover
 Drummer - Ian Paice
 Keyboard player - Jon Lord

Mark III (3) (1973–1975):
David Coverdale and Glenn Hughes were hired to replace Ian Gillan and Roger Glover. Glenn Hughes also had singing talent so it was decided he would act as lead singer on some of the band's songs too. Ritchie Blackmore left after he became more unhappy with the style of music of the band, which was more funk rock at this time.

 Lead singer - David Coverdale
 Guitar player - Ritchie Blackmore
 Bass player - Glenn Hughes (also occasional lead singer)
 Drummer - Ian Paice
 Keyboard player - Jon Lord

Mark IV (4) (1975–1976):

After making the hard decision to carry the band on without Blackmore, the band hired American guitar player Tommy Bolin and carried on the funk-rock music style Blackmore was unhappy about.

 Lead singer - David Coverdale
 Guitar player - Tommy Bolin
 Bass player - Glenn Hughes
 Drummer - Ian Paice
 Keyboard player - Jon Lord

Mark V (5) (1989–1992)
Ritchie Blackmore had before played with Joe Lynn Turner in Blackmore's solo band called Rainbow, and suggested he join the band to replace Ian Gillan, who was brought back 3 years later because of record label pressures, as the band's 25th anniversary was coming up and they wanted the iconic Mark II lineup together again.

 Lead singer - Joe-Lynn Turner
 Guitar player - Ritchie Blackmore
 Bass player - Roger Glover
 Drummer - Ian Paice
 Keyboard player - Jon Lord

Mark VI (6) (1993–1994):

The band still needed to play concerts after Ritchie Blackmore, so they hired American guitar player Joe Satriani, although he did not stay with the band after the tour.

 Lead singer - Ian Gillan
 Guitar player - Joe Satriani
 Bass player - Roger Glover
 Drummer - Ian Paice
 Keyboard player - Jon Lord

Mark VII (7) (1994–2002):
Joe Satriani turned down the chance to be a member of Deep Purple, so the band found another American guitar player called Steve Morse. In 2002, Jon Lord retired from the band after 26 years with them (not counting the 8 years the band was split up) leaving Ian Paice as the only founding member left. He was replaced with Don Airey.

 Lead singer - Ian Gillan
 Guitar player - Steve Morse
 Bass player - Roger Glover
 Drummer - Ian Paice
 Keyboard player - Jon Lord

Mark VIII (8) (2002–present)

This has remained the lineup since Jon Lord's departure from Deep Purple and the hiring of Don Airey to replace him.

 Lead singer - Ian Gillan
 Guitar player - Steve Morse
 Bass player - Roger Glover
 Drummer - Ian Paice
 Keyboard player - Don Airey
Discography
Studio albums
 Shades of Deep Purple (1968)
 The Book of Taliesyn (1968)
 Deep Purple (1969)
 Deep Purple in Rock (1970)
 Fireball (1971)
 Machine Head (1972)
 Who Do We Think We Are (1973)
 Burn (1974)
 Stormbringer (1974)
 Come Taste the Band (1975)
 Perfect Strangers (1984)
 The House of Blue Light (1987)
 Slaves and Masters (1990)
 The Battle Rages On... (1993)
 Purpendicular (1996)
 Abandon (1998)
 Bananas (2003)
 Rapture of the Deep (2005)
 Now What! (2013)
 Infinite (2017)
 Whoosh! (2020)
Turning to Crime (2021)

Other websites 
 Deep Purple Official Website www.deeppurple.org 
 The Highway Star

1968 establishments in England
1960s British music groups
1970s British music groups
1980s British music groups
1990s British music groups
2000s British music groups
2010s British music groups
Blues bands
English hard rock bands
English heavy metal bands
Musical groups established in 1968
Warner Bros. Records artists