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
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
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.