Fr

Francium-229

Protons (Z)

87

Neutrons (N)

142

Mass number

229

Half-Life

50.2 s

Abundance

---

Mass

229.038 u

Mass Excess

35,668.0 keV

Spin

(1/2+)

Discovered

1975

Binding energy per nucleon

7,618 keV

Neutron separation energy

5,787 keV

Proton separation energy

6,864 keV

Decay Mode

β⁻Radium-229100%

Decay chain

Francium-229Z 87 · N 14250.2 s
β⁻100%
β⁻100%
β⁻100%
α100%
β⁻100%
α~100%
α~100%
α99.992%
β⁻97.91%
α100%
β⁻100%
α100%