Na

Sodium-21

Protons (Z)

11

Neutrons (N)

10

Mass number

21

Half-Life

22.46 s

Abundance

---

Mass

20.998 u

Mass Excess

-2,184.86 keV

Spin

3/2+

Discovered

1940

Binding energy per nucleon

7,766 keV

Neutron separation energy

17,107 keV

Proton separation energy

2,432 keV

Decay Mode

β⁺Neon-21100%

Decay chain

Sodium-21Z 11 · N 1022.46 s
β⁺100%