Question

₈₈Ra²²⁶ experiences three α - decay. Find the number of neutrons in the daughter element.

Answer 1

Given: Mass number of ₈₈Ra²²⁶ = 226

Atomic number of ₈₈Ra²²⁶ = 88

Mass number of α = 4

Atomic number of α = 2

After 3 α decay, Mass number of the daughter element will be,

= 226 − (3 × 4)

= 226 − 12

= 214

Atomic number of daughter element is,

= 88 − (3 × 2)

= 88 − 6

= 82

∴ Number of neutrons = 214 − 82

= 132