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Chemical compound | Definition, Examples, & Types | Britannica
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 - Britannica
Substances are either chemical elements or compounds. A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.
Chemistry | Definition, Topics, Types, History, & Facts | Britannica
Cooking, fermentation, glass making, and metallurgy are all chemical processes that date from the beginnings of civilization. Today, vinyl, Teflon, liquid crystals, semiconductors, and superconductors represent the fruits of chemical technology.
Chemical element | Definition, Origins, Distribution, & Facts | Britannica
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 composed. Learn more about the origins, distribution, and characteristics of chemical elements in this article.
Bismuth | Properties, Uses, Symbol, & Facts | Britannica
The principal chemical application of bismuth is in the form of bismuth phosphomolybdate (BiPMo 12 O 40), which is an effective catalyst for the air oxidation of propylene and ammonia to acrylonitrile.
Chemical bonding | Definition, Types, & Examples | Britannica
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 emerged and developed into a powerful description of the structure of matter.
DDT | Description, History, Effects, Uses, Banned, & Facts | Britannica
The chemical was widely used, though many species of insects rapidly developed resistant populations. As a result of repeated sprayings, DDT accumulated in soils in surprisingly large amounts (10–112 kilograms per hectare [10–100 pounds per acre]).
Nitric oxide | Uses, Facts, & Definition | Britannica
Nitric oxide, colourless toxic gas that has important chemical signaling functions in animals and is a serious air pollutant.
Chemical formula | Definition, Types, Examples, & Facts | Britannica
Chemical formula, any of several kinds of expressions of the composition or structure of chemical compounds. The forms commonly encountered are empirical, molecular, structural, and projection formulas.
chemical energy - Kids | Britannica Kids | Homework Help
The chemical energy in food is converted, or changed, by the body into moving mechanical energy and heat energy. People have invented ways to use the chemical energy of substances to power machines.
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