Yttrium-91 (Y-91)

Identity

Protons

39

Neutrons

52

Mass number

91

Mass

90.9 ± 2.0 u

Mass excess

-86.351 MeV

Spin

1/2-*

Stability

Half-life: 58.5 days

Natural occurrence

Not found in nature

Decays to

• beta minus → Zr-91