Hydrogen-1

Properties and data of the isotope ¹H.

Contents

General Data

Parent Nuclides

NMR Data

Isotones und Isobares

Literature

Hydrogen-1 is the isotope of the chemical element hydrogen with mass number 1, also known under the names protium and light hydrogen. The atomic nucleus of the nuclide consists of a proton. With a proportion of 99.98%, H-1 is not only the most common isotope of natural terrestrial hydrogen, but it is also the lightest and most abundant nuclide in the universe (approx. 90% of all atoms).

General data

Name of the isotope:Hydrogen-1; H-1Other names:ProtiumSymbol:¹H or 11HMass number A:1 (= number of nucleons)Atomic number Z:1 (= number of protons)Neutrons N:0Isotopic mass:1.0078250322(6) u (atomic weight of Hydrogen-1)Nuclide mass:1.0072765 u (calculated nuclear mass without electrons)Mass excess:7.28897 MeVMass defect:-2.0000001654807E-10 u (per nucleus)Nuclear binding energy:-1.9E-7 MeV (per nucleus)
-1.9E-7 MeV (average binding energy per nucleon)Half-life:stableSpin and parity:
(nuclear angular momentum)1/2+Magnetic dipole moment:μ(μ_N) = +2.792847351(28)Charge radius:0.8783(86) femtometer fmYear of discovery:1920

Parent Nuclides

Direct parent isotope is: ⁹B.

Occurrence

Comparison of the natural Hydrogen isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Hydrogen Isotopic mixture	1.008 u	100 %
Isotope ³H	3.01604928132(8) u	[trace]	12.32(2) a	1/2+
Isotope ¹H	1.0078250322(6) u	99.99 % [99.972 - 99.999 %]	stable	1/2+
Isotope ²H	2.0141017781(8) u	0.01 % [0.001 - 0.028 %]	stable	1+

NMR data

Nuclear magnetic properties of the NMR active Nuclide ¹H

Isotope:¹H-NMRQuantity:99.99 % [99.972 - 99.999 %]Spin:1/2+Nuclearmagnetic moment
μ/μ_N:+2.792847351(28)Gyromagnetic ratio γ:26.675222 · 10⁷ rad T^-1 s^-1Nuclear g-factor:g_l = 5.585694702Resonance frequency:v₀ = 42.5759 at 1 TFrequency ratio:Ξ(¹H) = 100.0000 %Relative Sensitivity:1.00000 (H₀ = const.)
1.00000 (v₀ = const.)
[related to ¹H = 1.000]Reference compound:
(conditions)1% solution of tetramethylsilane (TMS, Me₄Si) in Chloroform-d (CDCl₃).

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 0) and isobaric (same nucleon number A = 1) with Hydrogen-1. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 0	Isobar A = 1
1	¹H	¹H
3	³Li

External data and identifiers

InChI Key:YZCKVEUIGOORGS-IGMARMGPSA-NSMILES:[1H]PubChem:ID 5460654Adopted Levels, Gammas:NuDat 1H

Literature and References

[1] - Juven Wang, Zheyan Wan, Yi-Zhuang You:
Proton stability: From the standard model to beyond grand unification.
In: Physical Review D, 106, 025016, (2022), DOI 10.1103/PhysRevD.106.025016.

[2] - Seth Koren:
A Note on Proton Stability in the Standard Model.
In: Universe, 8(6), 308, (2022), DOI 10.3390/universe8060308.