Hydrogen-4

Properties and data of the isotope ⁴H.

Contents

General Data

Radioactive Decay

Isotones und Isobares

See also: List of individual Hydrogen isotopes (and general data sources).

General data

Name of the isotope:Hydrogen-4; H-4Symbol:⁴H or 41HMass number A:4 (= number of nucleons)Atomic number Z:1 (= number of protons)Neutrons N:3Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):3 (= neutron-proton ratio)Neutron excess (N-Z):2Isotopic mass:4.02643(11) u (atomic weight of Hydrogen-4)Nuclide mass:4.0258814 u (calculated nuclear mass without electrons)Mass excess:24.61939 MeVMass defect:0.0073897799999996 u (per nucleus)Nuclear binding energy:6.88353573 MeV (per nucleus)
1.72088393 MeV (average binding energy per nucleon)Half-life:13.9 zsDecay constant λ:4.986670363740 × 10⁺²¹ s^-1Specific activity α:7.507607838129 × 10⁺⁴⁴ Bq g^-1
2.029083199494 × 10⁺³⁴ Ci g^-1Spin and parity:
(nuclear angular momentum)2-Isobaric spin: 1Mirror nucleus:Lithium-4Year of discovery:1981

Radioactive Decay

Half-life T_½ = 13.9 zs respectively 1.39 × 10^-22 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
n	³H	100 %	23.51(11) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 3) and isobaric (same nucleon number A = 4) with Hydrogen-4. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.