O

Oxygen-21

Protons (Z)

8

Neutrons (N)

13

Mass number

21

Half-Life

3.42 s

Abundance

---

Mass

21.009 u

Mass Excess

8,062.0 keV

Spin

(5/2+)

Discovered

1968

Binding energy per nucleon

7,389 keV

Neutron separation energy

3,806 keV

Proton separation energy

20,997 keV

Decay Mode

Decay chain

Oxygen-21Z 8 · N 133.42 s
β⁻100%
β⁻100%