Chemical compound | Definition, Examples, & Types | Britannica
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 …
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.
Chemical compound - Elements, Molecules, Reactions | Britannica
Chemical compound - Elements, Molecules, Reactions: Chemical compounds may be classified according to several different criteria. One common method is based on the specific elements present. For example, oxides contain one or more oxygen atoms, hydrides contain one or more hydrogen atoms, and halides contain one or more halogen (Group 17) atoms.
Molecule | Definition, Examples, Structures, & Facts | Britannica
An atom of sodium (Na) donates one of its electrons to an atom of chlorine (Cl) in a chemical reaction, and the resulting positive ion (Na +) and negative ion (Cl −) form a stable ionic compound (sodium chloride; common table salt) based on this ionic bond.
chemistry - Students | Britannica Kids | Homework Help
A compound has a definite composition—its constituent elements always occur in the same proportion, or formula. Water, for example, always contains two hydrogen atoms for every oxygen atom. The number of known compounds, both natural and artificial, is in the millions.
Ionic compound | Description, Examples, & Uses | Britannica
Dec 24, 2024 · 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.
molecule - Kids | Britannica Kids | Homework Help
Other molecules contain atoms of two or more different elements. A substance made of such molecules is called a chemical compound. Water is a chemical compound because its molecules have two hydrogen atoms and one oxygen atom. The sugar called glucose is …
Base | Definition, Examples, & Facts | Britannica
Broader definitions of a base, to include substances that exhibit typical basic behaviour as pure compounds or when dissolved in solvents other than water, are given by the Brønsted-Lowry theory and the Lewis theory.
chemistry - Kids | Britannica Kids | Homework Help
Each element has certain properties. When elements are combined, they form a new substance with its own properties. A substance formed in this way is called a compound. There are a little more than 100 elements. But there are millions of compounds.
Chemistry | Definition, Topics, Types, History, & Facts | Britannica
Nov 22, 2024 · Chemistry, the science of the properties, composition, and structure of substances (defined as elements and compounds), the transformations they undergo, and the energy that is released or absorbed during these processes.