Actinium-225 (Ac-225)

Identity

Protons

89

Neutrons

136

Mass number

225

Mass

225.0 ± 5.1 u

Mass excess

21.637 MeV

Spin

3/2-

Stability

Half-life: 9.92 days

Natural occurrence

Not found in nature

Decays to

• alpha → Fr-221 (no page)

Produced by

• Ra-225
• Pa-229