Krypton-81 (Kr-81)

Identity

Protons

36

Neutrons

45

Mass number

81

Mass

80.9 ± 1.2 u

Mass excess

-77.696 MeV

Spin

7/2+*

Stability

Half-life: 2.29 × 10⁵ years

Natural occurrence

Not found in nature

Decays to

• electron capture → Br-81