neutral atom

chemistry

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 1, 2026

Quick Summary

A neutral atom is the fundamental building block of all matter and chemistry. It consists of a nucleus containing positively charged protons and neutral neutrons, surrounded by negatively charged electrons. In a neutral atom, the number of electrons equals the number of protons, balancing the charges. The number of protons, known as the atomic number, defines the chemical element and its place in the periodic table. Electrons orbit the nucleus in shells, and the arrangement of electrons in the outermost shell, the valence shell, determines how an atom interacts with others, dictating its chemical properties.1234

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

5 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

Milky Way Galaxy
The general interstellar medium
…mostly of hydrogen in its neutral form. Radio telescopes can detect neutral hydrogen because it emits radiation at a wavelength of 21 cm. Such radio wavelength is long enough to penetrate interstellar dust and so can be detected from all parts of the Galaxy. Most of what astronomers have learned…
Read More
…mostly of hydrogen in its neutral form. Radio telescopes can detect neutral hydrogen because it emits radiation at a wavelength of 21 cm. Such radio wavelength is long enough to penetrate interstellar dust and so can be detected from all parts of the Galaxy. Most of what astronomers have learned…
Read More