Barium-133 (Ba-133)

Identity

Protons

56

Neutrons

77

Mass number

133

Mass

132.9 ± 1.1 u

Mass excess

-87.554 MeV

Spin

1/2+*

Stability

Half-life: 10.5 years

Natural occurrence

Not found in nature

Decays to

• electron capture → Cs-133