Rhenium-187 (Re-187)

Identity

Protons

75

Neutrons

112

Mass number

187

Mass

186.96 ± 0.79 u

Mass excess

-41.217 MeV

Spin

5/2+*

Stability

Half-life: 4.16 × 10¹⁰ years

Natural occurrence

62.60 % of rhenium

Decays to

• beta minus 100.0 % → Os-187
• alpha 0.0 % → Ta-183