Po

Polonium-221

Protons (Z)

84

Neutrons (N)

137

Mass number

221

Half-Life

2.2 m

Abundance

---

Mass

221.021 u

Mass Excess

19,774.0 keV

Spin

(9/2+)

Discovered

2010

Binding energy per nucleon

7,684 keV

Neutron separation energy

3,560 keV

Proton separation energy

8,475 keV

Decay Mode

β⁻Astatine-221100%

Decay chain

Polonium-221Z 84 · N 1372.2 m
β⁻100%
β⁻100%
β⁻78%
α~100%
α99.992%
β⁻97.91%
α100%
β⁻100%
α100%