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atomic number

Number of protons found in the nucleus of an atom

EntityQ23809

Also known as atom number · proton number · number of protons

Subclass of: number of entities
, physical quantity

Overview

From Wikipedia, the free encyclopedia · Read full article · Text CC BY-SA 4.0

The atomic number or nuclear charge number of a chemical element is the charge number of its atomic nucleus. For ordinary nuclei composed of protons and neutrons, this is equal to the proton number (np) or the number of protons found in the nucleus of every atom of that element. The atomic number can be used to uniquely identify ordinary chemical elements. In an ordinary uncharged atom, the atomic number is also equal to the number of electrons.

Overview

All data

35 statements · 14% with external sources · numbers in brackets are citations

Main Wikidata property: atomic number
ISQ dimension: 1
Quantity symbol (LaTeX): Z
Recommended unit of measurement: 1
1
Sources
1.Stated in ISO 80000-10:2019 Quantities and units — Part 10: Atomic and nuclear physics
View statement on Wikidata ↗
Counts: proton
Characteristic of: chemical element nature of statement: defining quality

On other databases

26 identifiers linking atomic number across the web's reference databases

Data quality

statements

14%

externally sourced

Source last edited October 1, 2026. AIDB refreshes this page daily.

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AIDB. (2026). atomic number (Q23809). Retrieved from https://aidb.si/e/atomic-number-Q23809