Bi

Bismuth-221

Protons (Z)

83

Neutrons (N)

138

Mass number

221

Half-Life

2.0 s

Abundance

---

Mass

221.026 u

Mass Excess

24,200.0 keV

Spin

(9/2-)

Discovered

2009

Binding energy per nucleon

7,668 keV

Neutron separation energy

4,831 keV

Proton separation energy

7,219 keV

Decay Mode

Decay chain

Bismuth-221Z 83 · N 1382.0 s
β⁻
β⁻100%
β⁻100%
β⁻78%
α~100%
α99.992%
β⁻97.91%
α100%
β⁻100%
α100%