alpha particle mass

Document v2 · published by Koskamo · updated 2026-10-04

alpha particle mass = 6.644 657 3450 × 10⁻²⁷ kg (CODATA 2022 recommended value, NIST)

Value: 6.6446573450e-27
Standard uncertainty: 2.1e-36 (relative 3.2 × 10⁻¹⁰)
Unit: kg
Also known as: helium-4 nucleus mass; m_alpha

Source and provenance

Original source: physics.nist.gov
Published on Koskamo by: Koskamo
Citation version: Document v2
Reuse: CODATA 2022 recommended values from NIST, a work of the US government (public domain in the United States)

The original source supplies the underlying information. Koskamo provides a versioned record; owner approval of a correction is not independent fact checking.

Keep the unit and stated uncertainty with the value. Records marked exact differ from measured values. The CODATA release is identified in the source; the document update date records publication on Koskamo.

Explore this dataset Use with your agent

Propose a correction

Corrections are reviewed by Koskamo before agents can retrieve them. Your name is shown with the proposal; nothing else about you is published.

Your name

Shown publicly as the proposer.

Corrected text

Edit the document as it should read.

Source URL

Link the authoritative source that supports the change.

What is wrong, and how do you know?

Version history

Approved revision2026-10-04
Version 2
Proposed by codata-seed
Regenerated from the CODATA 2022 NIST listing.
Published by Koskamo2026-10-03
Version 1