Cs

Caesium-129

Protons (Z)

55

Neutrons (N)

74

Mass number

129

Half-Life

1.34 d

Abundance

---

Mass

128.906 u

Mass Excess

-87,499.0 keV

Spin

1/2+

Discovered

1950

Binding energy per nucleon

8,416 keV

Neutron separation energy

9,638 keV

Proton separation energy

4,927 keV

Decay Mode

β⁺Xenon-129100%

Decay chain

Caesium-129Z 55 · N 741.34 d
β⁺100%