AcharyaChanakya/simple-wikipedia huggingface dataset:
The series is set in Los Angeles, California. It tells the story of the Forrester family, who owns a fashion empire called Forrester Creations. The major members of the family are Eric Forrester (played by John McCook), the president of Forrester Creations, his wife Stephanie (Susan Flannery), their eldest son Ridge (Ronn Moss) and Brooke Logan (Katherine Kelly Lang), who was married to both the father and the son. She owns most of Forrester Creations. This is because she created "BeLieF", a formula which earned much money for the company. There used to be a second fashion company called Spectra Fashions. It was Forrester’s main competitor. The conflicts between the Forrester and the Spectra families was one of the major themes of the story.
Primary color
Primary colors (or primary colours) are sets of colors that can be combined to make a useful range of colors. The primary colors are those which cannot be created by mixing other colors in a given color space.
For subtractive combination of colors, as in mixing of pigments or dyes for printing, the CMYK set of primaries is often used. In this system the primary colors are cyan, magenta,and yellow. Other sets include the RYB system of red, yellow, blue, especially used by artists.
For additive combination of colors, as in overlapping projected lights or in television and computer screens, the primary colors normally used are red, green, and blue.
Primary colors are not a fundamental property of light but are related to the physiological response of the eye to light (the way the eye works). For humans, three primary colors are usually used, since human color vision is trichromatic.
Fundamentally, light is a continuous spectrum of the wavelengths that can be detected by the human eye, an infinite-dimensional stimulus space. However, the human eye normally contains only three types of color receptors, called cone cells. Each color receptor respond to different ranges of the color spectrum. Humans and other species with three such types of color receptors are known as trichromats.
The additive primaries are red, green,
and blue. Because of the response curves of the three different color receptors in
the human eye, these colors are optimal in the sense that the largest range
of colors — a gamut — visible by humans can be generated by mixing light of these colours.
Additive mixing of red and green light, produce shades of yellow or orange. Mixing green and blue produces shades of cyan, and mixing red and blue produces shades of purple and magenta. Mixing equal proportions of the additive primaries results in shades of grey; when all three colors are fully saturated, the result is white. The color space that is generated is called the RGB ("red, green, blue") color space.
Media that use reflected light and colorants to produce colors are using the subtractive color method of color mixing. In the printing industry, to produce the varying colors, apply the subtractive primaries yellow, cyan, and magenta together in varying amounts. Subtractive color works best when the surface or paper, is white, or close to it.
Mixing yellow and cyan produces shades of green; mixing yellow with magenta produces shades of red, and mixing magenta with cyan produces shades of blue. In theory, mixing equal amounts of all three pigments should produce shades of grey, resulting in black when all three are fully saturated, but in practice they tend to produce muddy brown colors. For this reason, a fourth "primary" pigment, black, is often used in addition to the cyan, magenta, and yellow colors.
The color space generated is the so-called CMYK color space. The abbreviation stands for "Cyan, Magenta, Yellow, and Black" — K stands for "Kohle" (German for coal) and is used to represent black as 'B' could be confused with 'Blue'.
In practice, mixtures of actual materials like paint tend to be less precise. Brighter, or more specific colors can be created using natural pigments instead of mixing, and natural properties of pigments can interfere with the mixing. For example, mixing magenta and green in acrylic creates a dark cyan - something which would not happen if the mixing process were perfectly subtractive.
The umbilicus (also called navel or bellybutton) is a place on the body of mammals that is left after a baby loses its umbilical cord. The umbilicus of humans is in the middle of the abdomen. It is usually only easy to see on humans, and is a thin line on many other mammals. In humans, they can be split into two different kinds, the kind that goes in (innie) and the kind that goes out (outie). Different people have different navels that can be different in size, shape, and looks, but these differences are not genetic (you do not get them from looks passed down in your family). The hepatic portal vein passes from the umbilical vein to the liver. When a person becomes fat, the fat usually goes around the umbilicus.
It marks the water shed line of the body. The venus blood & lymph do not cross the umbilical plane.
James Cook
Captain James Cook, FRS (27 October 1728 – 14 February 1779) was a British explorer, navigator and cartographer. He made three voyages to the Pacific Ocean, mapping many areas and recording several islands and coastlines on European maps for the first time. He is most notable for the British finding the east coast of Australia, finding the Hawaiian Islands and for making the first maps of Newfoundland and New Zealand.
During his lifetime, he sailed twice around the world. He crossed the Antarctic Circle and found new islands and landscapes in North America and the South Pacific. During his trips, he spent a lot of time on science experiments, and mapping new areas. He also wrote a lot of books about what he found.
Cook was born on 27 November 1728 in Marton in Yorkshire in England. He was a son of a Scottish farmer. He was educated at the school in Great Ayton, and at 17 he began work in a shop at Staithes. At 18, Cook became a sailor, and became an apprentice to John Walker of Whitby. Walker's business was transporting coal. Cook learned mathematics and navigation from Walker. He studied as much as he could about navigation and science. He was sent on three expeditions with the ship called "Endeavour" all over the world.
His goals on these missions were:
Captain Cook was killed in Hawaii in a dispute about a stolen boat.
He had four sons and one daughter. Their names were Elizabeth Cook, Hugh Cook, George Cook, Nathaniel Cook and  Joseph Cook. His father’s name was James Cook. He had 3 sisters and 2 brothers. Their names were Mary Cook, who died at age 4, Margaret Cook, William Cook, Jane Cook and John Cook.
Offside rule
The offside rule is one of the oldest football rules, but is still a much discussed rule. This is probably because of the relatively complicated set of provisions provided by the sport's law-making body, the IFAB for deciding if a player in an offside position is actually guilty of an offside offence by becoming involved in active play. It can also be a difficult decision for the referee or assistant referee to make as they need to watch the ball, the player playing the ball and also the attacker who is seeking to receive the ball at the same time.
Offside is an offence committed by the team which has the ball and is punished with an indirect free kick.
It is a common misconception that the ball must be played forward for an offside offence to be committed. This is incorrect however, as an offside offence is related to the position of the player in relation to the last two opponents, the ball and the opponent's goal line rather than the direction the ball is played. If the player is closer to the opponent's goal line than both the ball and the second-last opponent when it is played by a team mate, she or he is in an offside position.
But there are some exceptions:
Valentine's Day is a celebration that happens on February 14. It is the day of the year when lovers celebrate their love. This can be done by giving flowers, chocolates, Valentine's cards or just a nice gift. Love notes can be given to one another. These notes that people give out are also called "valentines". Some people pick one person and call them their "Valentine" as a gesture to show love and appreciation.
Symbols of Valentine's Day are heart shapes, roses, and Cupid with his arrows.
Valentine's Day is named for the martyred Christian saint named Valentine. He was a bishop that married forbidden couples.
Since the 14th century, Valentine's pairs are formed in England. English emigrants then took the Valentine's custom to the United States. After World War II, US soldiers brought this festival to Europe.
In the third century A.D., Valentine was the bishop of Terni (Italy). He performed weddings for couples who were not allowed to get married. They may not have been allowed to get married because the parents did not agree with the connection or because the bridegroom was a soldier or a slave, so the marriage was forbidden. Valentine gave the married couple flowers from his garden. That's why flowers play a very important role on Valentine's Day. This did not please the emperor. On February 14, 269 AD, Valentine was beheaded because of his Christian faith.
An expansion of the legend combines the day of death of Valentine with the Roman festival Lupercalia. It was the festival of the great goddess Lupa, which is the feminine word for wolf. She was the Great She-Wolf who nursed the twin babies, Romulus and Remus, who later became the founders of Rome. During the annual ceremony, the temple priestesses (lupae) wrote their names on strips of papyrus. These were picked by young men. After the lottery, the youngsters walked through the city and got the blessings of the citizens. The martyr Valentine became the patron saint of the lovers. Still in the Middle Ages, as in France or in Belgium, people were chosen by the lottery to live a year with each other and people prayed to Saint Valentine to make love potions and charms.
In the 19th century, the custom of sending Valentine's Cards became very popular. The cards usually have pictures of hearts or flowers and contain some sort of poem, message, or code. Codes and simple messages give some people the to show their true feelings to the person they love. Today, some people still use mysterious codes to show their love. People can use newspapers to give a coded message to their loved one, giving other readers a view of the couples' intimacy with one another. Sometimes they will give each other chocolates.
Famous for the popularity of the celebration is the folk song called "Die Vogelhochzeit" ("The Birds' Wedding").
In China, a holiday called Qi Xi is also called "Chinese Valentine's Day", especially by younger people. Qi Xi is traditionally held on the 7th day of the 7th month of the lunar calendar. In recent years, it has become more like Valentine's Day in other countries.
Canary Islands
The Canary Islands are a group of islands off the coast of Morocco. They are an autonomous community of Spain (they make their own laws). There are seven main islands. The people who live there speak Spanish. The autonomous community has two capital cities, of equal status: Santa Cruz de Tenerife and Las Palmas de Gran Canaria. Like the other islands of Macaronesia, they were created by volcanoes on the bottom of the sea. Those volcanoes slowly rose above the water and became islands. This process lasted many thousands of years.
The islands have a very long and interesting history. When Europeans first came to the Canary Islands, they found people already living there. These people were called the Guanches. Many of the Guanches were killed in 15th century battles with the Spanish, and the ones who remained adopted the Spanish way of life. After the Spanish conquest many battles were also fought against pirates. Most recently Morocco was interested in them.
After the Spanish conquest many Europeans settled there. Portuguese and Spaniards, and also Belgians and Maltese were among the early settlers. Recently many people from all over Europe, America, India and Africa have also become citizens or permanent residents.
The seven islands are: La Palma, La Gomera, El Hierro, Tenerife, Gran Canaria, Lanzarote, and Fuerteventura. People from La Gomera have a whistle language that children there learn at school. Tenerife has the highest mountain in the Canary Islands and Spain too, the Teide. The Teide is actually a volcano, but it has not been active in more than 300 years.
The islands are popular with tourists because of their warm climate and nice beaches. The local farmers grow lots of exotic fruits including papayas and bananas.
The Canary Islands' main exports include bananas and tobacco.
Edinburgh Airport
Edinburgh Airport (IATA EDI, ICAO: EGPH) is an airport in Scotland. It is one of seven airports in the United Kingdom owned by the company BAA, which also owns Glasgow Airport and Aberdeen Airport in Scotland.
On 19th October 2011, BAA Limited said that it is going to sell Edinburgh Airport. This was done following a decision by the UK's Competition Commission which said that BAA needs to sell either Glasgow or Edinburgh Airport.
In February of 2001 a Shorts 360 crashed shortly after taking off from Edinburgh Airport. Both pilots were killed but there were no passengers on board as it was a mail-carrying flight.
Lufthansa
Lufthansa is the largest airline in Germany, and the second-largest in Europe. Some of Lufthansa's hubs are Frankfurt am Main and Munich, Germany. A hub is an airport where people who fly from one city to a second city can transfer or change airplanes.
Lufthansa buys airplanes from Boeing and Airbus. Lufthansa has big airplanes for flights to North America, Asia, and Africa. These flights are called long-haul flights because they are between cities that are far apart from each other. Lufthansa also has small airplanes for flights in Europe. These flights are called short-haul flights.
Lufthansa is a member of the Star Alliance, which means it is a partner with other airlines like United Airlines and Air Canada. Members of the Star Alliance cooperate or work together to schedule their flights better so that travelling is easier for passengers or people.
The name of Lufthansa's frequent flyer program is Miles and More. People earn points for flights they travel on. When they have enough points, they can get a free flight. Lufthansa has "Miles and More" to encourage people to fly with Lufthansa.
Many regional flights are operated Lufthansa Regional with Lufthansa CityLine, Eurowings and Air Dolomiti.
Lufthansa uses these aeroplanes:
Orlando Jonathan Blanchard Bloom (born 13 January 1977, in Canterbury, Kent, England) is an English actor. He is most known for his first major movie role as the elf Legolas Greenleaf in "The Lord of the Rings" movie trilogy.
In 1993, he moved to London to improve his career, doing bit parts in TV series like "Casualty". Then he played some theatres like "The Seagull", "Twelfth Night", and "Trojan Women". This is a role that he received some days before graduating the drama school in London.
Here are some movies, in which he played an important character:
871
The year of 1791 started on a Saturday in the Gregorian calendar.
Year 1084 (MLXXXIV) was a leap year starting on Monday (link will display the full calendar) of the Julian calendar.
Chromium is a chemical element. Its symbol on the periodic table (a list of all the elements) is Cr. It always has 24 protons, so its atomic number is 24. Its mass number (number of protons and neutrons) is about 54. Most of the times it has 28 neutrons, but different isotopes have more or fewer neutrons. As a metal, it has 24 electrons. Its ions have fewer electrons.
Chromium is a shiny metal. It is reactive, but it reacts with air to produce a very thin coating of chromium(III) oxide, which prevents it from rusting any more.
Chromium occurs in several oxidation states; +2, +3, and +6 are most common. It forms chemical compounds that are colorful.
There are two main types of chromium ions, which are found in chromium compounds. One type of chromium ion ("Cr", trivalent chromium ) is required by our body and by those of other animals. If we do not get enough chromium, certain parts of our body may not work properly. We get most of the chromium we need from our food we eat. Chromium is also put into vitamins to make sure that we get enough. If we get too much of this type of chromium, it can harm our body.
Another type of chromium ("Cr" (chromate, hexavalent chromium), in the +6 oxidation state) can cause cancer or make people sick, even though most people do not get exposed to it much. It is found in places that make chromium metal, which is why they need to be cleaned up when they close. Hexavalent chromium can be destroyed by reacting it with reducing agents, turning it into Cr (trivalent chromium). They are strong oxidizing agents.
The chromate ion is CrO. Chromates are generally yellow.
The dichromate ion is CrO. Dichromates are red or orange.
Chromium occurs as chromite. Chromite is a mixture of iron(II) oxide and chromium(III) oxide. Its chemical formula is FeCrO. It is heated with sodium carbonate to make sodium chromate, iron(III) oxide, and carbon dioxide. The sodium chromate is reacted with sulfuric acid to produce sodium dichromate. The sodium dichromate is reduced by carbon to chromium(III) oxide. The chromium(III) oxide is reacted with aluminum to make chromium metal. The chromates and dichromates are what make chromium production areas toxic.
Chromium is used in different metal products. Stainless steel is the most common use. It is also used in "chrome plating", where it makes things shiny and stops corrosion. Some chromates were used as pigments, but they are toxic so people do not want to use them anymore.
Chromium metal is nontoxic. But hexavalent chromium is toxic and carcinogenic, and trivalent chromium is mildly toxic in large quantities.
Neon is a noble gas. It is chemical element 10 on the periodic table. Its symbol is Ne.
The word "neon" comes from the Greek word meaning "new". It was discovered by William Ramsay and Morris W. Travers in 1898.
Neon does not react with other elements, so it is found by itself. There is not much neon in the air, and it is clear, so we do not see it.
Neon gas is used in gas discharge lamps. When electricity goes through the neon, it lights up red. Due to this quality, it is used in signs. Similar signs use other gases to make other colors, but they are also often called "neon signs".
Neon is also a term referring to a type of color that is very bright, such as lime green.
No true chemical compounds including the neutral compounds of neon are known. Where there is the helium compound HHeF, which might be stable, the analogous compound with Neon is not.
Tin is a chemical element with symbol Sn (for ) and atomic number 50. It is in Group 14 on the periodic table. It is not radioactive.
Tin is a silver, somewhat soft metal. It is a post-transition metal. Its melting point is 231.93°C and its boiling point is 2602 °C. It can melt easily in a flame. It is malleable. It makes a crackling sound called tin cry when a piece of it is bent. Tin has more non-radioactive isotopes than any other element.
Tin is found in two allotropes: alpha-tin and beta-tin. Alpha-tin is a brittle, dull, powdery, semimetallic form of tin. It is made when very pure tin is cooled. Beta-tin is the normal shiny, soft, conductive, metallic form. It is made at higher temperatures. The decay of tin by turning from beta-tin to alpha-tin is called "tin pest". Alpha-tin is not wanted in many places. When small amounts of other elements like antimony are added, the tin cannot change into alpha-tin. When alpha-tin is heated, it changes into beta-tin.
Tin can be hardened by adding antimony or copper, as well as some other elements. These also make it resistant to tin pest. Tin can also be made very shiny. Tin can make an alloy with copper called bronze.
Tin resists many corrosive substances and is often used to protect other metals. Salt water and fresh water do not affect tin. It dissolves in strong acids to make tin salts. It reacts with some strong bases.
Tin forms chemical compounds in two oxidation states: +2 and +4. +2 compounds are reducing agents. Some of them are colorless while others are colored. +4 compounds are more unreactive and act more covalent.
Tin burns in air to make tin(IV) oxide, which is white. Tin(IV) oxide dissolves in acids to make other tin(IV) compounds. Tin(IV) chloride is a colorless fuming liquid when anhydrous and a white solid when hydrated. It easily reacts with water to make tin(IV) oxide and an acid again.
Tin reacts with hydrohalic acids to make tin(II) halides. For example, tin(II) chloride is made when tin dissolves in hydrochloric acid. Tin(IV) halides are made when tin reacts with the halogens. Tin(IV) chloride is made when tin reacts with chlorine. Tin(II) sulfate is different as it does not oxidize to tin(IV) sulfate. Tin(II) oxide is a blue-black solid that burns in air to make tin(IV) oxide.
+2 compounds are reducing agents. They are about as common as +4 compounds. Some are colorless, while others are colored.
+4 compounds are unreactive. Some are colorless.
Tin is not found as a metal in the ground. It is normally in the form of cassiterite. Cassiterite is a mineral containg tin(IV) oxide. The cassiterite is normally found downstream of the cassiterite deposit when it is by a stream or river. Tin is also found in some complicated sulfide minerals.
Tin does not have any major job in the human body.
Tin is made by heating cassiterite with carbon in a furnace. China is the biggest maker of tin.
People discovered tin long ago and used it with other metals. When copper and tin are mixed together, bronze is made. Bronze was important in the past, because it was one of the strongest metals available, which meant it was useful in weapons and tools. Bronze changed the world when it was first invented, starting the Bronze Age. People organized themselves more, because making tools from bronze was harder than making them from rock and wood like they did before.
Tin is used in solder. Solder used to contain a mixture of lead and tin. Now the lead is removed because of its toxicity.
Tin is also used to make pewter, which is mainly tin mixed with a small amount of copper and other metals. Babbitt metal also has tin in it. Tin is used to coat several metals, like lead and steel. Tin plated steel containers are used to store foods. The pipes on a pipe organ are made of tin. Tin foil was used before aluminium foil. Tin was one of the first superconductors to be found. Organotin compounds are more common than almost any other organometal compound. They are used in some PVC pipes to stop them from decaying. Organotin compounds are toxic, though.
Tin is not toxic, but tin compounds are very toxic to marine life. They are a little toxic to humans.
Silicon is a chemical element. Its atomic number is 14 on the periodic table. Its symbol is Si. It is a hard, brittle crystalline solid. It is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic table.
Silicon looks like a metal, but does not do everything a metal does, like conduct electricity very easily. Silicon is used as a great deal in today's computers and virtually every electronic device. Germanium can also be used in computers, but silicon is easier to find.
There is a lot of silicon on the Earth. At the beach, there is silicon in the form of sand. Sand is a compound of silicon known as silicon dioxide or silica. Glass is made by heating sand (or silicon dioxide) hot enough. The glass can have different colours by adding coloured compounds. Silicon also makes up a lot of different rocks and minerals, and they are known as silicates.
Silicon is a semiconductor, and much used in computers. A super-pure isotope of silicon, silicon-28, can now be made 40 times more pure than before. It is very important for the next big development in computers. This stores "qubits" in atoms of another element, like phosphorous, embedded in a tiny layer of ultra-pure silicon-28. These qubits can simultaneously encode a one and a zero, for incredibly fast and complex calculations.
Cadmium
Cadmium is a metal. It is element 48 on the periodic table. Its symbol is "Cd". Its atomic number is 48 and its atomic mass is 112.4. It is found in Group 12 on the periodic table.
Cadmium is a blue-gray soft metal. It can be considered a transition metal or a post-transition metal. It is malleable and ductile. It is similar to zinc. It melts at 321°C.
Cadmium has 8 natural isotopes. 5 are radioactive, but 3 have very long half-lives so their radioactivity is almost nothing.
Cadmium is a moderately reactive metal. It corrodes in moist air and dissolves in acids. It burns in air when powdered to make the brown cadmium oxide.
Cadmium forms chemical compounds in two oxidation states: +1 and +2. The +1 state is rare and unstable. The +2 state is much more common. Most +2 compounds dissolve easily in water and are white to yellow. Cadmium oxide can be brown, red, or white. Cadmium sulfide is bright yellow. Cadmium chloride and cadmium sulfate are colorless solids that dissolve easily in water. Cadmium fluoride is slightly soluble. Cadmium compounds are toxic when inhaled.
Cadmium was found by two chemists, German chemist Friedrich Stromeyer discovered it in 1817, and Karl Herman also discovered it in 1818. They were looking at an impurity in zinc carbonate and found cadmium. For about 100 years, Germany made most cadmium. Cadmium iodide was used as a medicine although it was toxic.
Cadmium ores are rare. Greenockite, a cadmium sulfide mineral is the only main ore and it is found with sphalerite, a zinc sulfide. Because of this, most cadmium comes from zinc processing. Cadmium as a metal is very rare but is found in one place in Russia.
China makes the most cadmium. South Korea and Japan also make cadmium. Cadmium is taken from the zinc metal by heating the zinc metal in a vacuum. Cadmium is boiled first. The cadmium is condensed and used. Cadmium is also taken by precipitating it from the solution of zinc sulfate used to make pure zinc by electrolysis.
In the 1930s and 1940s cadmium was mainly used to plate steel to prevent it from corroding. Then cadmium sulfide was used as a pigment in paint.
Now, cadmium is mainly used in nickel cadmium batteries. 86% of cadmium is used in batteries as of 2009. Some people are trying to stop using nickel-cadmium batteries because cadmium is toxic. Cadmium is still used to electroplate steel to prevent corrosion. Only about 6% of cadmium is used for this. Cadmium is also used in lasers, nuclear reactors, phosphors, photoresistors, pigments, and semiconductors. Wood's metal, an alloy that melts very easily, has cadmium in it. Cadmium is used in some solder.
Cadmium is not used in the human body or any other animal. A diatom uses cadmium, though.
Cadmium is a highly toxic metal. Dust of cadmium or its compounds is very dangerous and can kill. Some countries have banned cadmium from electronics. Cigarette smoking is the most important source of cadmium. Smokers have about 4 times more cadmium in their blood than nonsmokers (people who do not smoke). Cadmium is thought to be carcinogenic, although people still debate whether it is other things with the cadmium that cause cancer, like arsenic.
Krypton
Krypton is a noble gas which means it does not react with many other elements. It is clear and has no taste or smell. The atmosphere is only about one millionth part krypton. The name "kypton" comes from the Greek word "kryptos" meaning hidden. It is used in fluorescent lamps, flashbulbs, and as a wavelength standard. The metre used to be defined as 1,650,763.73 wavelengths in a vacuum of krypton gas. Krypton has very few compounds.
The main use for krypton is to make light. There is one main type of krypton light bulbs. This is called a gas discharge lamp. There are three main types of these. First is a low energy gas discharge lamp or "neon light". Low energy gas discharge lights made from krypton are near white to green. Second is a high energy short length of time gas discharge light or "flash bulb". These are mostly used for photography. They are bright blue-white. Third is a high energy gas discharge light. This third kind is mostly used to light airport runways. They are also bright blue-white.
Krypton is number 36 on the periodic table. Its symbol is Kr.
Krypton was found by Sir William Ramsay and Morris Travers in Great Britain in 1898. Ramsay was given the 1904 Nobel Prize in Chemistry for his work on noble gases. It was a difficult gas to discover; Ramsay suspected it existed but only found it by removing other gases. This is why he gave it the name Krypton. There is no mineral called Kryptonite or planet called Krypton, which features in the Superman comics by Jerry Siegel and Joe Shuster. The fictional planet is probably better known than the real chemical element called Krypton.
Noble gas
The noble gases are a group of elements that are all gases. These elements are all in group 18 of the periodic table. All of them are monoatomic, meaning each molecule is a single atom. They almost never react with other elements. This is because they have a full 8 electrons outer electron shell. There are six noble gases:
All of these gases are found in air. They make up around 0.96% of the atmosphere. Noble gas compounds can be formed from noble gases.
When the noble gases are used in cold cathode tubes to produce light, each of them has a different colour. Since Radon is radioactive, it is usually not used for lighting. Here are pictures of what the others look like:
Oganesson (element 118) is probably the next noble gas after Radon because it is the next box down in the same group. However it has a half life of 0.89 ms, after which it decays to Livermorium (Element 116). This means its use is probably limited.
Noble gases were discovered by Lord Rayleigh and Sir William Ramsay. Rayleigh won the Nobel Prize in Physics in 1904 for his work on noble gas. Ramsay won the Nobel Prize in Chemistry in 1904 for his work with noble gas.
Polonium
Polonium is a rare radioactive metalloid. It is chemical element 84 on the periodic table and its symbol is Po. It was discovered in 1898 by Marie and Pierre Curie.
Polonium is highly unstable, radioactive and toxic. This makes it difficult to handle. It can be dangerous, even in very small amounts. One gram of Po will self-heat to a temperature of about . It also vaporizes easily.
Polonium has 33 isotopes, and all of them are radioactive. It is a very rare element in nature because of its short half-life. It is a breakdown product of uranium, so it is found in uranium ores.
Polonium is also very important because it the main element of nuclear bombs.
Bismuth is a chemical element. It is element 83 on the periodic table and its symbol is "Bi". Its atomic mass is 209. It is only slightly radioactive. The radioactivity is minimal so it is typically seen as nonradioactive. Bismuth is only naturally found as one isotope, which is the almost nonradioactive one. Its radioactivity was predicted by scientists and proven by analyzing the metal. It is in Group 15 on the periodic table.
Bismuth is a silver metal with a pink tinge to it. This pink color is because of its oxide coating. Bismuth is a post-transition metal. It is one of the strongest diamagnetic metals. It is almost as heavy as lead. Its melting point is quite low , which is normal for post-transition metals. It is quite brittle. It can make crystals with a shiny surface. As a liquid it is heavier than as a solid. Another chemical that does this is water. It does not conduct electricity or heat very well.
Bismuth is somewhat similar to antimony. Bismuth makes a thin coating of bismuth(III) oxide when it is in air. This makes the colors on the crystals. It does not oxidize any more than the oxide layer. It burns when powdered with a bright blue flame, making yellow bismuth(III) oxide fumes. Bismuth reacts with sulfur when molten as well. Bismuth reacts with nitric acid to make bismuth(III) nitrate and concentrated sulfuric acid to make bismuth(III) sulfate and sulfur dioxide. It reacts with the halogens to make bismuth(III) halides. With fluorine it makes bismuth(V) fluoride unless the fluorine is diluted, though.
Bismuth forms chemical compounds in two main oxidation states: +3 and +5. +3 is more common. +3 compounds are weak oxidizing agents and are normally light yellow. +5 compounds are strong oxidizing agents. Bismuthates are the most common +5 compounds. Bismuth(V) fluoride is another +5 compound. Bismuth(V) oxide is an unstable red solid. Bismuth sulfide is a common ore of bismuth. Bismuthine, a bismuth hydride, is very unstable and only can be made at very cold temperatures. Bismuth makes many oxy- compounds like bismuth oxychloride. These compounds are made when bismuth halides dissolve in water.
+3 compounds are weak oxidizing agents except for bismuthine. They are normally pale yellow.
Bismuth(V) oxides (+5 compounds) are very strong oxidizing agents. Its chemical formula is BiO. It is a scarlet red solid. It decomposes to bismuth(III) oxide and oxygen easily. It is made by electrolysis of bismuth(III) oxide in a hot concentrated alkali like sodium hydroxide.
Bismuth was known since ancient times. It was confused with tin and lead, though. No one is credited for discovering bismuth. In the 1500s, people started realizing that bismuth was different than tin or lead.
Bismuth is not very common in the earth. It is only about twice as common as gold. Bismite, a bismuth oxide mineral, and bismuthinite, a bismuth sulfide, are two common ores. Bismuth is sometimes found as a metal, too.
Bismuth and its minerals are too rare to be mined. They are gotten by "secondary extraction". It is normally found in lead metal. The lead metal is purified by electrolysis, leaving the bismuth behind as a sludge on the bottom of the container. The copper is taken out of the sludge and the bismuth is purified by being reduced in a furnace and all the impurities are filtered out.
China makes the most bismuth. Peru, Mexico, and Japan also make bismuth.
Bismuth can also be recycled. This is difficult in many places because bismuth is used for things like bullets, solder, and stomach medicine that get scattered all over and cannot easily be gotten again.
Bismuth is used in alloys with very low melting points. Some of them melt in hot water. They are also found in solder that does not have lead in it. It can make alloys with other metals to make them more malleable. It is also used in bullets to replace lead. In some places lead bullets are outlawed as birds eat them and get lead poisoning. It is also used in alloys for plumbing. It is used in fishing sinkers.
Bismuth is used in some medicines such as Pepto-Bismol. This medicine has bismuth subsalicylate in it. It is also used as an internal deodorant and to treat eye infections and peptic ulcers.
Bismuth oxychloride is used in cosmetics. Bismuth telluride is used in electronic thermometers. Another compound is used in superconductors and becomes a superconductor at a high temperature. It can be used as a pigment and in fireworks to make crackling sounds. It is used in the nuclear fuel of a nuclear reactor.
Bismuth is much less toxic than other heavy metals. This is why it is replacing lead in many things. It does not add up in the body like other heavy metals do. A very large amount of bismuth can poison the kidneys and liver, though. Because its oxide does not dissolve in water, it is considered safe for the environment.
Iridium
Iridium is the 77th element on the periodic table. Its symbol is Ir. Ir's atomic number(the amount of protons) is 77.
Iridium is a metal. Like other metals in the platinum group, Iridium is a rare and expensive "noble metal" and is a transition metal. It looks like platinum and is found in asteroids and comets. Iridium deposits are used to identify relative dates of collisions of foreign bodies. Iridium can fold and bend just like aluminum, and remains very shiny. Most iridium is found in the Americas, though some is mined in Myanmar, South Africa, and Russia. Iridium melts at 2410 °C, and boils at 4130 °C. It is the most corrosion resistant metal.
Iridium is not needed in the body.
A man named Smithson Tennant first found it in the year 1803. Smithson Tennant found it in the remains when he left crude platinum in a mixture of hydrochloric acid and nitric acid.
Transition metal
The transition metals are a group of metals that are found in the middle of the periodic table. The alkaline earth metals, beginning with beryllium are to the left and the boron group elements are to the right. The term "transition element" was invented for them in 1921.
The atomic numbers of these metals are from 21-30, 39-48, 57, 72-80, 89 and 104-112. Many elements like Zn, Cd, Hg, La and Ac have a highly debatable position in the transition series of elements. La and Ac are also classed in the lanthanide series and actinide series respectively.
Transition metals have several general properties. They are harder and less reactive than the alkaline earth metals. They are also harder than the post transition metals. They make colorful chemical compounds with other elements. Most of them have more than one oxidation state. Like other metals, they are electrical conductors.
Some of the transition metals are necessary to keep humans healthy, such as iron, zinc, and chromium. Other elements in the transition metals can be harmful to our body, like cadmium and mercury. Other elements like gold or silver do not harm or help us. There are more transition metals than any other groups in the periodic table.
Only a few of the transition metals are colored; most of them are silver-gray or silver-bluish.
Osmium is a chemical element. It is element number 76 on the periodic table. Its symbol is "Os".
There is not much osmium on earth. There is actually such a small amount that osmium is very expensive.
Osmium is a metal and it does not react very much, and such a metal is known as a "noble metal".
Osmium is the densest (heaviest for the same amount) element on the periodic table.
It was discovered in 1804 by Smithson Tennant in London, England. He found it together with Iridium in a bit of Platinum, which he had dissolved in Aqua regia.
Radon is element 86 on the periodic table. Its symbol is Rn.
Radon is a gas and is part of the group known as the noble gases. It does not react with other elements, so it is found pure.
Radon is radioactive, meaning that it can give off harmful rays. Some people have high levels of radon in their houses, and this can be very dangerous. A lot of radon can get stuck in the basement of old houses, and so people end up breathing it in. It gets stuck in the lungs and has been known to cause cancer. There are groups that try to make sure there is no dangerous radon in houses.
FTP, also known as File Transfer Protocol, is a communication protocol for the rapid, simple transmission of files across a network supporting the TCP/IP. This network is generally the Internet, or a local network. FTP is a way of accessing files on another computer. FTP uses the Client-Server architecture, meaning that there is a server, that holds the files, and does the authentication, and a client, or the end-user, who is accessing the files. The server listens on the network for connection requests from other computers. The client can make a connection to the FTP server by using FTP client software. Once connected and authenticated (via rsh or SFTP) the client can do things such as uploading files to the server, downloading files (taking the server's files and putting them on his own computer) from the server, and renaming, deleting files on the server, changing file permissions, etc.
Most modern operating systems support FTP. This implies that any computer connected to a TCP/IP based network can manipulate files on another computer on that network regardless of which operating systems are involved, provided that they are open to FTP connections. There are many existing FTP client and server programs, many of these are available free, or open source.
FTP connection is also seen in cellular phones when trying to transfer or receive data from a computer nearby.
FTP server return codes show their status by the digits within them. A short explanation of various digits' meanings are given below:
FTP may run in "active" or "passive" mode, which determines how the data connection is established. In both cases, the client creates a TCP control connection from a random, usually an unprivileged, port N to the FTP server command port 21.
Some popular open source FTP server implementations are:
Hypertext Transfer Protocol (often abbreviated to HTTP) is a communications protocol. It is used to send and receive webpages and files on the internet. It was developed by Tim Berners-Lee and is now coordinated by the W3C. HTTP version 1.1 is the most common used version today. It is defined in RFC 2616.
HTTP works by using a user agent to connect to a server. The user agent could be a web browser or spider. The server must be located using a URL or URI. This always contains http:// at the start. It normally connects to port 80 on a computer.
A more secure version of HTTP is called HTTPS (Hypertext Transfer Protocol Secure). This contains https:// at the beginning of the URL. It encrypts all the information that is sent and received. This can stop malicious users such as hackers from stealing the information and is often used on payment websites. HTTPS uses port 443 for communication instead of port 80.
The request message contains the following:
The request line and headers must all end with two characters: a carriage return followed by a line feed, often written <CR><LF>. The empty line must consist of only <CR><LF> and no other whitespace. In the HTTP/1.1 protocol, all headers except Host are optional.
A request line containing only the path name is accepted by servers to maintain compatibility with HTTP clients before the HTTP/1.0 standard.
Ethernet is a way of connecting computers together in a local area network or LAN. It has been the most widely used method of linking computers together in LANs since the 1990s. The basic idea of its design is that multiple computers have access to it and can send data at any time. This is comparatively easy to engineer.
If two computers send data at the same time, a collision will occur. When this happens, the data sent is not usable. In general, both computers will stop sending, and wait a random amount of time, before they try again. A special protocol was developed to deal with such problems. It is called Carrier sense multiple access with collision detection or CSMA/CD.
There are different Ethernet standards. Today, Ethernet cables look like thick telephone cables. They connect to boxes called hubs or switches. Each cable runs from a computer's network interface card (NIC) to such a box. This cable is called 10BaseT or 100BaseT, or 1000BaseT Cable.
All cable types:
Today, the cables for 10BaseT, 100BaseT, and 1000BaseT are the same. Their transmission medium is unshielded twisted pair for Category 5 (UTP-Cat5) or 5e. Shielded cable (STP-Cat5 or Cat5e) can be used when there is a lot of electrical noise, and Category 6 (UTP-Cat6 or STP-Cat6) works better with faster signals such as 1GBit or 10GBit.
Other devices, such as video game consoles, can also be connected using the same kind of cabling. Certain computer peripherals, for example printers and certain hard disks can be directly connected to the network with such cables.
Ethernet can go at different speeds. In the beginning, Ethernet was at 10 MBits per second. The Ethernet most often used today is at 100 MBits per second. Most new computers now have the NIC built in, and can go at 1GBit per second. There are also standards for 1GBit per second and 10 GBit per second. 100 MBit can usually talk to 10 MBit, and 1 GBit can talk to 100 MBit and usually to 10 MBit (both full and half duplex).
Obesity is the condition of being much too heavy for one's height so that one's health is affected. In other words, it means to be too overweight. Also known as being fat. It is considered a disease and has been described as an epidemic.
To know if a person is overweight, the body mass index (BMI) is calculated, by dividing the person's weight (in kilograms), by their height (in metres) squared (multiplied by itself). (This is only meaningful for adults who are fully grown, and should not be used for children. Growth charts can be used to measure obesity in children.)
A BMI between 18.5 and 25 is considered "normal". People with a BMI of 25 or more are said to be overweight; with 30 and above, they are considered obese, and with 35 and above, they are considered "severely obese" (this used to be called "morbidly obese"). In general, the BMI number is a good quantifiable measurement of a person's obesity. However, it is a poor predictor in people who are very athletic, because a person with a higher than average amount of muscle tissue will weigh more than an average person, thus resulting in a BMI that is higher than normal, even if that person is very large.
The most common cause for obesity is getting more calories than are used by the body. Other factors that often contribute to obesity are:
Genetics are known to contribute to obesity. Leptin is a hormone that is linked to obesity.
Many health problems are associated with obesity. An example is Type 2 diabetes. A woman with a BMI higher than 35 is 93 times more likely to develop diabetes. A 2009 review found that people with a BMI between 40 and 50 were 22.5 times more likely to die from diabetes than people with BMIs between 22.5 and 25.
An obese woman is more likely to have an unhealthy baby.
Risk is associated with where the excess fat is stored on the body. Abdominal obesity is particularly dangerous.
Some people think that the idea that obesity causes bad health is not completely true and has been exaggerated. An example is J. Eric Oliver. He wrote a book called "Fat Politics: The Real Story Behind America's Obesity Epidemic". There is evidence for this belief.
The Centers for Disease Control and Prevention said in 2003 that 400,000 people died because of being obese in 2000. Then in 2004 they said that the number was wrong. A 2013 review of scientific papers found that Grade 1 obesity (BMI 30-34.9) is not associated with increased deaths. Grades 2 (BMI 35-39.9) and 3 (40+) obesity are associated with much higher rates of death. It has been suggested that obesity is associated with mortality (death) because of mortality in Grade 2 and 3 obesity. People with grade 2 and 3 obesity are 29% more likely to die.
'Metabolically healthy obesity' is increasingly being recognized. Up to 40% of obese people are metabolically healthy. They are not more likely to get heart disease or die than metabolically healthy non-obese people.
The 'obesity paradox' is a term used to describe how obesity can lower the risk of death. Obesity increases the chance of getting heart disease. But obese people with heart disease are less likely to die in a 7-year period. The obesity paradox has also been found in patients with stroke, diabetes, and chronic obstructive pulmonary disease.
Scientists have not yet found a 'cure' for obesity that most people are willing to implement. It is common wisdom that people who lose weight will regain it all within 5 years.
However, this position has been scientifically challenged for over a decade. Additionally, modern research has achieved significantly higher success rates than the figure that dominates the popular internet. Therefore, diet and exercise is the most common recommended treatment for obesity - it has the potential for a very high treatment success rate.
Surgery can be used to treat obesity. Gastric bypass is the most common weight loss surgery. It makes a person's stomach smaller so that they feel full after eating less food and causes their body to absorb less calories. People who have surgery are usually very obese.
Some people think that obesity should not be treated at all. This position is contradicted by substantial medical research.
Weight loss medicines can make people want to eat less or make less of the energy from food be absorbed by their bodies. The only weight loss drug approved by the FDA for long term use is orlistat. The U.S. Food and Drug Administration has not approved other drugs because they have side effects. Also they are worried that people who are not obese will take them.