Helion molar mass

$M(h)$ = 3.014 932 250 10(94) × 10⁻³ kg mol⁻¹

Value: 3.014 932 250 10 × 10⁻³ kg mol⁻¹
Standard uncertainty: 9.4 × 10⁻¹³ kg mol⁻¹
Relative uncertainty: 3.1 × 10⁻¹⁰ (312 parts per trillion)
Status: Measured
Symbol: $M(h)$
Source: CODATA 2022 via NIST · NIST entry

Use in a calculation

# helion molar mass, CODATA 2022 (NIST)
helion_molar_mass = 3.0149322501e-3  # kg mol^-1, standard uncertainty 9.4e-13

# SciPy: scipy.constants.physical_constants['helion molar mass']

What it is

The mass of one mole of helions (helion), in kilograms per mole.

How the value changed, 1998–2022

Each point is one CODATA adjustment, plotted as its difference from the 2022 value; the bars show one standard uncertainty (an arrowhead means the bar runs off the chart).

Relative uncertainty

CODATA	Value (uncertainty)	Relative uncertainty	Change from previous
2022	3.014 932 250 10(94) × 10⁻³	3.1 × 10⁻¹⁰	+4.4 σ of 2018
2018	3.014 932 246 13(91) × 10⁻³	3.0 × 10⁻¹⁰	−5.0 σ of 2014
2014	3.014 932 246 73(12) × 10⁻³	4.0 × 10⁻¹¹	−0.0 σ of 2010
2010	3.014 932 2468(25) × 10⁻³	8.3 × 10⁻¹⁰	−0.2 σ of 2006
2006	3.014 932 2473(26) × 10⁻³	8.6 × 10⁻¹⁰	+0.7 σ of 2002
2002	3.014 932 2434(58) × 10⁻³	1.9 × 10⁻⁹	+10.1 σ of 1998
1998	3.014 932 234 69(86) × 10⁻³	2.9 × 10⁻¹⁰

“Change from previous” is the shift in the value divided by the standard uncertainty of the previous adjustment. Earlier values are converted into the current unit where NIST changed it (for example J s to J Hz⁻¹).