Chemical compound | Definition, Examples, & Types | Britannica
2024年10月18日 · Chemical compound, any substance composed of identical molecules consisting of atoms of two or more chemical elements. 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.
Molecule | Definition, Examples, Structures, & Facts | Britannica
2024年11月23日 · Molecule, a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance. Learn more about the properties and structures of molecules in …
Definition and classification of chemical compounds | Britannica
chemical compound, Any substance composed of identical molecules consisting of atoms of two or more elements. Millions are known, each unique, with unique properties. Most common materials are mixtures of compounds. Pure compounds can be obtained by physical separation methods, such as precipitation and distillation.
Ionic compound | Description, Examples, & Uses | Britannica
2024年10月12日 · ionic compound, any of a large group of chemical compounds consisting of oppositely charged ions, wherein electron transfer, or ionic bonding, holds the atoms together.
Organic compound | Definition & Examples | Britannica
2024年10月25日 · An organic compound is any chemical compound in which one or more atoms of carbon are covalently linked to atoms of other elements, most commonly hydrogen, oxygen, or nitrogen. The few carbon-containing compounds not classified as organic include carbides, carbonates, and cyanides.
Water | Definition, Chemical Formula, Structure, Molecule, & Facts ...
2024年11月3日 · Water, substance composed of the chemical elements hydrogen and oxygen and existing in gaseous, liquid, and solid states. It is one of the most plentiful of compounds and has the important ability to dissolve many other substances, which was essential to the development of life.
Chemical compound - Elements, Molecules, Reactions | Britannica
2024年10月18日 · The simplest chemical compounds are binary compounds—those consisting of two elements. Different rules apply for the nomenclature of binary ionic compounds and binary molecular (covalent) compounds, and so they will be considered separately.
Sugar | Definition, Types, Formula, Processing, Uses, & Facts
3 天之前 · Sugar, any of numerous sweet, colorless, water-soluble compounds present in the sap of seed plants and the milk of mammals and making up the simplest group of carbohydrates. The most common sugar is sucrose, a crystalline tabletop and industrial sweetener used in …
Ammonia | Definition & Uses | Britannica
2024年10月30日 · The ammonia molecule has a trigonal pyramidal shape with the three hydrogen atoms and an unshared pair of electrons attached to the nitrogen atom. It is a polar molecule and is highly associated because of strong intermolecular hydrogen bonding.
Methane | Definition, Properties, Uses, & Facts | Britannica
2024年11月12日 · Its chemical formula is CH 4. Chemical properties of methane methane structure The tetrahedral structure of methane (CH 4 ) is explained in the VSEPR (valence-shell-electron-pair repulsion) theory of molecular shape by supposing that the four pairs of bonding electrons (represented by the gray clouds) adopt positions that minimize their mutual ...