ejaasaari/simplewiki-2025-04-01 huggingface dataset:
Organic compounds are carbon-based compounds. Organic compounds contain carbon bonds in which at least one carbon atom is covalently linked to an atom of another type (usually hydrogen, oxygen or nitrogen). Most polymers are organic compounds. History. The name "organic" is a historical name from the 19th century. People believed that only living things could make organic compounds and "dead" things (such as minerals) could make inorganic compounds. However, Friedrich Wöhler proved this wrong by synthesizing urea, a well-known organic compound. Kinds of organic compounds. There are natural organic compounds, and synthetic ones. Their structure may be described by using names, and making diagrams.  One way of showing the molecule is by drawing its structural formula. Because molecules can have complicated structures, people have made ways to show them in simple language. One way is to use line diagrams. Each atom is shown by a letter, and connected by a line to each atom with which it is has a covalent bond. One line means a single bond, two lines means a double bond and so on.  Because there is in an infinite number of possible organic compounds, language is needed to give a unique name to each one. The International Union of Pure and Applied Chemistry, or IUPAC, made a system for doing this. Although an IUPAC name makes every single possible molecule unique, the names are often long and complicated, so in everyday life, "trivial" names--unofficial but widely understood names--are used, such as the trivial names Paracetamol, Tylenol, and Acetaminophen, which are used for a compound whose IUPAC name is "N-(4-hydroxyphenyl) acetamide". Some of these trivial names are trademarks. Natural Compounds. Natural compounds are compounds made by living beings. These could also be made in a lab, but many of these compounds are taken from nature because it is easier and less expensive to do it that way. For example, every year people grow and eat huge amounts of natural sugar and starch. Other common natural compounds are: amino acids, proteins, carbohydrates, many antibiotics like Penicillin and Am
Coal is a hard rock which can be burned as a fossil fuel. It is mostly carbon but also contains hydrogen, sulphur, oxygen and nitrogen. It is a sedimentary rock formed from peat, by the pressure of rocks laid down later on top. Peat, and therefore coal, is formed from the remains of plants which lived millions of years ago in tropical wetlands (coal swamps), such as those of the late Carboniferous period (the Pennsylvanian). Charcoal is made by wood heated in an airless space. Coal can be burned for energy or heat. About two-thirds of the coal mined today is burned in power stations to make electricity. Like oil, when coal is burned its carbon joins with oxygen in the air and makes a lot of carbon dioxide, which causes climate change. Many people die early because of illnesses from air pollution from coal. Most countries are turning to other sources of energy, such as solar power and wind power. But new coal power plants are still being built in some parts of the world, such as China. Coal can be roasted (heated very hot in a place where there is no oxygen) to produce coke. Coke can be used in smelting to reduce metals from their ores. History. Coal was the most important fuel of the Industrial Revolution. Coal was an important part of rail freight in the UK in the 20th century, forming the greater part of several companies' freight volume. Early in the 21st century most coal fired power stations in the United Kingdom and several other countries were closed to reduce greenhouse gas emissions. Types of coal. Under suitable conditions, plant material is transformed step by step into Diamond is commonly believed to be the result of this process, but this is not true. Diamond is carbon but is not formed from coal. Coal contains impurities. The particular impurities determine the use. Coking coal has little ash or sulfur or phosphorus. Those would spoil the iron made by the blast furnace. Environmental problems. Coal, when burnt, gives off almost a third more carbon dioxide per unit of energy than oil, and 80% more than natural gas. Almost half of the carbon dioxide from people is because of burning coal
Petroleum, (from Greek πέτρα - rock and έλαιο - oil) also called crude oil, is a thick and black liquid. It is a natural material mainly made of hydrocarbons. The hydrocarbons come from many billions of ancient phytoplankton. When they die, their bodies sink to the bottom. This formed basins of oil in many parts of the world. Most petroleum is found by drilling down through rocks on land or off-shore on the continental shelf. Major producers are in the Middle East, the Americas, and Russia. It is the most important world fuel source. It supplies 38% of the world's energy and is also used to make petrochemicals. Crude oil is a mixture of many different chemicals (mostly hydrocarbons), most of which burn well. It is separated into simpler, more useful mixtures by fractional distillation in oil refineries to give separate chemicals such as gasoline (or "petrol") for cars, kerosene for airplanes and bitumen for roads. The bitumen gives crude oil its dark black color; most of the other chemicals in crude are slightly yellow or colorless.  Petroleum can be easily transported by pipeline and oil tanker. Refined petroleum is used as fuels; mainly gasoline ("petrol") for cars, diesel fuel for diesel engines used in trucks, trains and ships, kerosene fuel for jets and as lubricants. Petrochemicals: Problems. Petroleum resource is limited and non-renewable. Some believe it will run out within 70 years after a peak oil early in the 21st century. Burning petroleum or other fossil fuel adds the carbon in the oil to the oxygen in the air to create carbon dioxide, which is an air pollutant. The carbon can be removed from the carbon dioxide by plants. There is a lot of crude oil left underground. Oil companies and experts quote "reserves" which some people confuse with the actual amount of oil underground. However, as an oil deposit is drained, making more come out of oil wells becomes more difficult and expensive, so "reserves" means the amount that is not too expensive.  Most of the crude left underground
Natural gas is a mixture of gases. It consists mainly of hydrocarbons. The main component is methane, which is a greenhouse gas. Natural gas is a natural resource, often found in the ground, either alone or together with petroleum. Landfills and natural processes produce a little methane. Usually it is transported to users in a pipeline. Most natural gas is burnt as a fuel to produce energy. It burns with a blue flame. Like other flames, this can cause pollution with nitrogen oxides. Natural gas is burned to produce electricity, to cook and to heat buildings. It is also used as fuel for natural gas vehicles for transport. When natural gas is burned in a power station it boils water into steam that spins a steam turbine that turns a generator to make electricity. Some power stations use natural gas in a gas turbine.  Natural gas is also converted into many different industrial chemicals. It is the most common feedstock for making pure hydrogen. Hydrogen is used as fuel in fuel cells, and to make ammonia. Ammonia is used as a fuel, as a fertilizer for crops, and for making many other things. Natural gas is also converted into monomers to make many plastic products.
Energy can mean various things: Scientific energy. In physics, energy is a property intrinsic to anything that is able to interact in the universe. The energy of an object is its capability of producing a force that can do work, as well as its capability of transferring heat. When an object does work on another object (changing its momentum), the former’s energy (its capability of doing work) decreases and the latter’s energy increases, by transferring it.  Basic forms of energy include: Conservation of energy. Energy is a property that is not created or destroyed, although energy can change in detectable form. This is a rule that is commonly understood as the "conservation law of energy". In respects to this rule, the total amount of energy that exists in an isolated system will always be the same, no matter what changes have been made to it.  In the early 20th century, scientist found that matter itself can be created from energy (energy and matter are interchangeable, in spite of everyday experiences). This is just another change of form. After these discoveries, the conservation law of energy was extended to become the conservation law of matter and energy: matter and energy can neither be created from nothing nor destroyed to the point of complete erasure from reality. Albert Einstein was the first to mathematically show this. (E = mc2)  Matter can be created from energy or converted into energy through processes such as nuclear fission or nuclear fusion. Types of energy. Scientists have identified many types of energy, and found that they can be changed from one kind into another. These include: For example: Measuring energy. Energy can be measured. The amount of energy a thing has can be given a number. As in other kinds of measurements, there are measurement units. The units of measurement for measuring energy are used to make the numbers meaningful. The SI unit for both energy and work is the joule (J). It is named after James Prescott Joule. 1 joule is equal to 1 newton-metre. In terms of SI base units, 1 J is equal to 1 kg m2 s−2. It is most often used in science, though particle physics often uses the electronvolt. The measurement for electricity most often uses the kilowatt-hour (kW·h). One kW·h is equivalent to 3,600,000 J (3600 kJ or 3.6 MJ).
Jewels (or gems or gemstones) are rare minerals. They usually come in colours and sizes. They begin in a rough rock form, but can be cut and polished to turn into a jewellery. However, some other non-mineral rocks (such as lapis lazuli) or organic materials can also be also used for jewelry and are called gemstones. These include amber or jet. Pearls and coral are sometimes also called gemstones. Most gemstones are hard. Soft minerals are used in jewelry too, because of their luster that gives them value.  Being rare or in short supply also makes a gemstone valuable. History. The Ancient Greeks began to decide which gems are precious and semi-precious. This continued in other cultures.  In modern times, the precious stones are diamond, ruby, sapphire and emerald, with all other gemstones being semi-precious.
Xenon is a non-metal chemical element. It has the chemical symbol Xe and atomic number 54. It is one of the few elements that are a gas at the standard temperature and pressure. History. Sir William Ramsay and M. W. Travers discovered this element in 1898. The element's name came from the Greek word "xenos", which means 'stranger'. Chemistry. Xenon belongs to the group of the noble gases. Noble gases are very unreactive. However, in 1962, chemists have found that xenon can react with fluorine under special conditions, such as high pressure and high temperature. It is not known why xenon behaves differently under these circumstances. There are also some compounds with oxygen. The gas is not very reactive, because if fulfills the octet rule. This means that a lot of energy is needed to remove an electron from xenon. This activation energy for xenon is 1172 kJ/mol. To remove a second electron from xenon, an energy of 2046.4 kJ/mol is needed. Known oxidation states of xenon are 0, +1, +2, +4, +6 and +8. However, the most stable form is pure xenon, or the xenon's oxidation state of 0. Xenon has 8 stable isotopes and more than 30 unstable isotopes. Uses. Xenon gas is used in electron tubes, bactericidal lamps, trobe lamps, and lamps used to excite ruby lasers. It has the atomic mass of 131.294 and is the 5th inert gas in the inner gas group. Xenon is also a trace gas in the atmosphere, occurring at 87 ±1 nL/L (parts per billion) or approximately 1 in 11.5 million. It is also emitted from some mineral springs.
Kuala Lumpu () is the capital city and the largest city of Malaysia and a Federal Territory. After Putrajaya was constructed in the late 1990s, the administrative capital has been moved there. Kuala lumpu has one of the tallest buildings in the world, the Petronas Twin Towers. Climate. Kuala lumpu has a tropical rainforest climate ("Af" in the Koeppen climate classification). The annual range of temperature in Kuala Lumpu is small, only 1°C. There is no distinct seasonal difference in temperature in the city. Kuala Lumpu is hot throughout the year. The annual mean temperature are 26.5 °C (79.7 °F). The annual rainfall in Kuala lumpu is high (2393mm). The rainfall distribution is even in the city, with heavy rainfall all the year. In April and November, the monthly rainfall is slightly higher. Mayors of Kuala Lumpur. Since Kuala lumpu became a Federal Territory of Malaysia on February 1, 1972, the city has been led by seven mayors. They are:
The speed of light, in any medium, which is usually denoted by formula_1, is a physical constant important in many areas of physics. It is denoted by "c0" especially in vacuum medium, although the symbol 'c' can be used to refer to that in any medium. It is exactly by definition. A photon (particle of light) travels at this speed in a vacuum.  According to special relativity, formula_1 is the maximum speed at which all energy, matter, and physical information in the universe can travel. It is the speed of all massless particles such as photons, and associated fields—including electromagnetic radiation such as light—in a vacuum.  It is predicted by the current theory to be the speed of gravity (that is, gravitational waves). Such particles and waves travel at formula_1 regardless of the motion of the source or the inertial frame of reference of the observer. In the theory of relativity, formula_1 interrelates space and time, and appears in the famous equation of mass–energy equivalence . The special theory of relativity is based on the prediction, so far upheld by observations, that the measured speed of light in a vacuum is the same whether or not the source of the light and the person doing the measuring are moving relative to each other. This is sometimes expressed as "the speed of light is independent of the reference frame." Example explaining how speed does not depend on reference frame. This behavior is different from our common ideas about motion as shown by this example: George is standing on the ground next to some train tracks (railroad). There is a train rushing by at . George throws a baseball at in the direction the train is moving. Tom, a passenger on the train, has a device (like a radar gun) to measure throwing speeds. Because he is on the train, Tom is already moving at in the direction of the throw, so Tom measures the speed of the ball as only . In other words, the speed of the baseball, as measured by Tom on the train, depends on the speed of the train. In the example above, the train was moving at 1/3 the speed of the ball, and the speed of
Denial is a word used in psychology on defense mechanism. It means that someone denies that something has happened or is happening although he really knows it is true. Usually this happens because admitting it would cause a lot of pain. Denial is usually the first state of coping with loss. For example, if someone close to a person dies, the survivor's first feeling might be denial, or refusal to accept the fact that the person is really dead. Denial, is also when you think that a team (like in football) will win a football match before its even started and refuse to accept the fact thet they could lose Denial, is also when you refuse to accept the fact that someone else did something (like change something) when you 'think you know' it was a different person
Tokyo () is the capital and largest city of Japan. It is on the island of Honshu in the region of Kanto. Tokyo is the center of the Japanese government. The Imperial Palace is in Tokyo but it's not actually public for tourists to visit. Tokyo is the center of business, trade, and industry of Japan. The city is the center of the largest metropolitan area in the world. It faces Tokyo Bay. It became the capital city of Japan in the middle of 19th century, when its name changed from "Edo" to "Tokyo". Before then, Kyoto was the capital of Japan. The Emperor of Japan, or Tenno, lived in Kyoto. Edo was the place where the Tokugawa Shoguns lived. The city grew up under the control of the shoguns. Before then it was a small town on the sea. Edo means "the mouth of a river" in Japanese. Tokyo was destroyed by fires started by the Great Kantō earthquake in 1923. It was also badly damaged by bombs during World War II. After Japan lost the war, the city was rebuilt. History. 1457-1869. Tokyo began as a small fishing village named Edo(江戸、えど). Edo was in the old Musashi Province.  The Edo clan built walls to protect the town in the late 12th century. In 1457, Ōta Dōkan built Edo Castle. In 1590, Tokugawa Ieyasu made Edo his base. He became shogun in 1603, and the town became the center of his military government. This marked the beginning of the Edo period. During this time, Edo grew into one of the largest cities in the world. More than one million people lived there by the 18th century. Edo was not the capital of Japan. The emperor lived in the capital, Kyoto. However, since the shogun was more powerful than the emperor throughout Japanese history, Edo had more power. After about 263 years, the Meiji Restoration removed the shogun from power. In 1869, the
Laozi (Lao Tsu, Lao-Tze) was a Chinese philosopher best known for Taoism, the Tao Te Ching, and becoming a deity of Taoism and Chinese folk religions. A legendary figure of Chinese culture, Laozi may have lived during the Warring States period. Laozi's work influenced anti-authoritarian and Legalist philosophers. What was his real name? Laozi's personal name is supposedly "Li Er" (李尔). His courtesy name is "Boyang" (伯阳). A popular posthumous name is "Li Dan" "Lǐ Dān"). During the Tang dynasty, he was called the "Supremely Mysterious and Primordial Emperor" "Tàishàng Xuānyuán Huángdì"). Many people of the Li family say they descended from Laozi. For example, the emperors of the Tang dynasty claimed this. This family was known as the Longxi Li lineage (隴西李氏). Although these are questionable, they show Laozi's impact on Chinese culture. Who was he? Was he even real? Some philosophers don't think he was real. Some think the Daodejing was "a compilation of Taoist sayings by many hands". The first mention to Laozi is in the "Records of the Grand Historian" by Sima Qian. In one account, he was an official who lived around the time of Confucius. His name was "Er Li" or "Dan Li", and he wrote some a book with two parts before leaving west. In another, he has the name "Lao Laizi", and the book has 15 parts. In a third, he appears as a royal astrologer named "Lao Dan" living at the time of Duke Xian during the Qin Dynasty. The oldest Daodejing writing comes from around 375 BCE. According to traditional accounts, Laozi worked as the Keeper of the Archives (librarian) during the Zhou. He was able to study the works of the Yellow Emperor and other classics. Laozi never opened a school but still
Brass is an alloy of copper and zinc. Some types of brass are called bronzes. Brass has a golden appearance. It is harder than pure metals and resists corrosion. It costs more than zinc. There are some common brasses: Things brass are used to make include: Properties. Brass is more malleable than bronze or zinc. The melting point of brass can be 900 to 940 °C or 1,650 to 1,720 °F, depending on what it is made of. The density of brass is 8.4 to 8.73 g/cm3 (0.303 to 0.315 lb/cu in).  Today, almost 90% of all brass alloys are recycled. Brass is not ferromagnetic. Brass scrap is collected and transported to the foundry. In the foundry, it is melted and recast into billets. The billets are heated and stretched into the form and size that is wanted. Brass will corrode when it is exposed to moisture, chlorides, acetates, ammonia, and some acids. Brass alloys. There are many brass alloys. They include:
A body is the physical material of a person or organism. It is only used for organisms which are in one part or whole. There are organisms which change from single cells to whole organisms: for example, slime moulds. For them the term 'body' would mean the multicellular stage. Other uses: The body of a dead person is also called a corpse or "cadaver". The dead bodies of vertebrate animals and insects are sometimes called "carcasses". The human body has a head, neck, torso, two arms, two legs and the genitals of the groin, which differ between males and females. The study of the body is anatomy.  The study of the workings of the body is physiology. The word body is sometimes used in other ways. For example, a lake is a body of water. The laws on a topic are a "body of law". An astronomy object is a "celestial body".
An alloy is a uniform mixture. It is made up of two or more chemical elements, of which at least one is a metal. An alloy has properties different from the metals it is made of. Most alloys are made by melting the metals, mixing them while they are liquid to form a solution, then leaving them to cool and turn solid again. Theory. Combining a pure metal with one or more other metals or non-metals often makes it better. For example, steel is an alloy made from iron but it is stronger than iron. Physical properties like density, reactivity and electrical and thermal (heat) conductivity may not be much different than the elements (substances) which make the alloy. But, properties like strength can be very much different. The first alloy to be discovered was Bronze. Bronze is made from copper and tin. Bronze was discovered a very long time ago in the prehistoric period. Then, bronze was being used for making tools and weapons. This period was known as Bronze Age. But, later better alloys were discovered which replaced bronze for making tools and weapons. Now, bronze is used for making ornaments, statues, and bells. Brass is another alloy made from copper and zinc. Melting point is the temperature at which a solid changes to liquid. Most alloys do not have a single melting point. They have a melting range in which the alloy is a mixture of solid and liquid stages. The temperature at which melting just starts is called solidus and the temperature at which the melting is just finished is called liquidus. Terms related to alloys. The term alloy means a mixture of atoms in which the main substance or the primary constituent is a metal. This primary metal is called the "base" or "matrix". If an alloy has only two types of atoms, like copper-nickel alloy, then such an alloy is called "binary alloy". If an alloy has three types of atoms, like iron, nickel and chromium, then it is called a "ternary alloy". An alloy with four types of atoms is called a "quaternary alloy" and an alloy with five types of atoms is called a "quinary alloy". Different varieties or forms of alloys can be made from the same constituent materials (substances from which the alloy is formed). These different forms or varieties can be formed by using different amounts of the constituents. Some common alloys. There are some common alloys:
Material is what everything that you can touch is made of. Even material that is too small to touch, is called material. We use materials to make things. We can also call material "physical substances." "Raw" material is materials such as ores which we can clean and mix with other materials to make another material like steel, for example. Cotton is a raw material used to make textiles, which are used to make clothes. Material is not matter, though. Matter is everything in existence. Material is used for things that have use. Refined materials are materials that have been refined, like metal, reduced or converted into better, more useful materials like clothes and tools. Refined materials are usually mixes of other materials, like glue or steel.