
Chemical compound | Definition, Examples, & Types | Britannica
Dec 16, 2025 · All the matter in the universe is composed of the atoms of more than 100 different chemical elements, which are found both in pure form and combined in chemical compounds.
Chemistry | Definition, Topics, Types, History, & Facts | Britannica
Dec 26, 2025 · Cooking, fermentation, glass making, and metallurgy are all chemical processes that date from the beginnings of civilization. Today, vinyl, Teflon, liquid crystals, semiconductors, and …
Chemical element | Definition, Origins, Distribution, & Facts | Britannica
Jan 9, 2026 · A chemical element is any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is …
Chemical synthesis | Organic & Inorganic Reactions | Britannica
Chemical compounds are made up of atoms of different elements, joined together by chemical bonds. A chemical synthesis usually involves the breaking of existing bonds and the formation of new ones.
Gold | Facts, Properties, & Uses | Britannica
Jan 24, 2026 · gold (Au), chemical element, a dense lustrous yellow precious metal of Group 11 (Ib), Period 6, of the periodic table of the elements. Gold has several qualities that have made it …
Sodium bicarbonate | Definition, Uses, & Formula | Britannica
Jan 21, 2026 · Sodium bicarbonate, white crystalline or powdery solid that is a source of carbon dioxide and so is used as an ingredient in baking powders, in effervescent salts and beverages, and as a …
Periodic table | Definition, Elements, Names, Symbols, Groups, Charges ...
Dec 22, 2025 · Periodic table, in chemistry, is an organized array of all the chemical elements in order of increasing atomic number. When the elements are thus arranged, there is a recurring pattern in …
Nitric oxide | Uses, Facts, & Definition | Britannica
Dec 27, 2025 · Nitric oxide, colourless toxic gas that has important chemical signaling functions in animals and is a serious air pollutant.
Cellular respiration | Definition, Equation, Cycle, Process, Reactants ...
Jan 9, 2026 · Cellular respiration, the process by which organisms combine oxygen with foodstuff molecules, diverting the chemical energy in these substances into life-sustaining activities and …
Salt | Chemistry, History, Occurrence, Manufacture, Uses, & Facts ...
Jan 8, 2026 · In the chemical industry, salt is required in the manufacture of sodium bicarbonate (baking soda), sodium hydroxide (caustic soda), hydrochloric acid, chlorine, and many other chemicals.