Chemical Elements

Nickel is the chemical element with atomic number 28 and the symbol Ni. It is a silvery metal in group 10 of the periodic table that resists corrosion even at high temperatures. Most nickel is used to make alloys such as stainless steel, and it also appears in coins, batteries and catalysts. History of nickel

Nitrogen is the chemical element with atomic number 7 and the symbol N. It is a colorless, odorless gas that makes up about 78 percent of Earth’s atmosphere by volume, and it is a building block of proteins and DNA. In the air it exists as pairs of atoms, N2, that are very unreactive, so

Oxygen is the chemical element with atomic number 8 and the symbol O. It is a colorless, odorless gas that makes up about 21 percent of the atmosphere by volume, and it is the most abundant element in the Earth’s crust when its compounds are counted. Most living things use oxygen to release energy from

Phosphorus is the chemical element with atomic number 15 and the symbol P. It is a nonmetal in group 15 of the periodic table that exists in several different forms, the best known being white, red and black phosphorus. All living things need phosphorus, and most of the element mined today goes into fertilizer. History

Platinum is the chemical element with atomic number 78 and the symbol Pt. It is a shiny, silvery-white metal that resists corrosion as well as gold does. Its main use is in catalytic converters for vehicles, and it also serves in jewelry, chemical manufacturing, electronics and cancer drugs. History of platinum Probably the oldest worked

Potassium is the chemical element with atomic number 19 and the symbol K. It is a soft, silvery alkali metal in group 1 of the periodic table that tarnishes within minutes in air and reacts violently with water. Potassium compounds are essential to living cells and are the main ingredient of many fertilizers. History of

Radon is the chemical element with atomic number 86 and the symbol Rn. It is a colorless, odorless, radioactive noble gas that forms naturally from the decay of radium and uranium in rocks and soils. Radon has no stable isotopes, and the main concern about it today is that it can build up indoors and

Selenium is the chemical element with atomic number 34 and the symbol Se. It sits in group 16 of the periodic table, below sulfur, and it exists as a silvery gray solid and as a red powder. The Royal Society of Chemistry calls it a semi-metal, while PubChem classifies it as a nonmetal. Selenium is

Silicon is the chemical element with atomic number 14 and the symbol Si. It is a hard, brittle metalloid in group 14 of the periodic table, and it is the second most abundant element in the Earth’s crust after oxygen. Pure silicon is the basis of modern electronics, and compounds of silicon make up most

Silver is the chemical element with atomic number 47 and the symbol Ag. It is a soft, shiny transition metal in group 11 of the periodic table that people have mined since ancient times. Silver is the best reflector of visible light known, and it is used in jewelry, mirrors, electrical contacts, solder and photography.