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.

Mar 2, 2026 · Cooking, fermentation, glass making, and metallurgy are all chemical processes that date from the beginnings of civilization. Today, vinyl, Teflon, liquid crystals, semiconductors, and …

Jan 13, 2026 · Substances are either chemical elements or compounds. A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.

Feb 19, 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 …

The tendency of an atom to combine is a chemical property of the atom, and it is controlled by electrical forces at the atomic level. Those forces forge the links, called chemical bonds, that hold two or more …

Feb 20, 2026 · The fundamental principles of chemical engineering underlie the operation of processes extending well beyond the boundaries of the chemical industry, and chemical engineers are …

Chemical reactions differ from physical changes, which include changes of state, such as ice melting to water and water evaporating to vapor. If a physical change occurs, the physical properties of a …

Feb 7, 2026 · Manganese, chemical element that is a silvery white, hard, brittle metal of Group 7 in the periodic table. It was recognized as an element in 1774 by the Swedish chemist Carl Wilhelm …

Jan 29, 2026 · This article begins by describing the historical evolution of the current understanding of chemical bonding and then discusses how modern theories of the formation of chemical bonds have …

In modern warfare, chemical weapons were first used in World War I (1914–18). Like nuclear and biological weapons, chemical weapons are often classified as weapons of mass destruction.