
Chemical compound | Definition, Examples, & Types | Britannica
Nov 11, 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.
Chemical reaction | Definition, Equations, Examples, & Types
Nov 30, 2025 · A chemical reaction is a process in which one or more substances, the reactants, are converted to one or more different substances, the products. Substances are either …
Chemistry | Definition, Topics, Types, History, & Facts | Britannica
Nov 8, 2025 · The identification of pure substances and the analysis of chemical mixtures enable all other chemical disciplines to flourish. The importance of analytical chemistry has never …
Chemical Definition & Meaning | Britannica Dictionary
CHEMICAL meaning: 1 : of or relating to chemistry; 2 : working by means of chemicals
Chemical formula | Definition, Types, Examples, & Facts | Britannica
Nov 1, 2025 · Chemical formula, any of several kinds of expressions of the composition or structure of chemical compounds. The forms commonly encountered are empirical, molecular, …
Chemical element | Definition, Origins, Distribution, & Facts
Nov 29, 2025 · A chemical element is any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which …
Chemical energy | Definition & Facts | Britannica
The chemical energy in food is converted by the body into mechanical energy and heat. The chemical energy in coal is converted into electrical energy at a power plant. The chemical …
chemical reaction - Students | Britannica Kids | Homework Help
The substances in a chemical reaction may be chemical elements, molecules, or compounds. The substances present at the start of a chemical reaction are called the reactants; the substances …
Chemical bonding | Definition, Types, & Examples | Britannica
3 days ago · 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 …
Chemical compound - Synthesis, Reactions, Properties | Britannica
Nov 11, 2025 · In general, a vast range of chemical compounds are synthesized for applications as fibres and plastics, pharmaceuticals, dyestuffs, herbicides, insecticides, and other products.