Question

The number of `alpha and beta`-particles emitted during the transformation of `._(90)Th^(232) " to " ._(82)Pb^(208)` are respectively
A. 4, 2
B. 2, 2
C. 8, 6
D. 6, 4

Answer 1

Correct Answer - D
`._(90)Th^(232) rarr ._(82)Pb^(208) + x ._(2)He^(4) + y ._(-1)beta^(0)`
Equating mass no.
`232 = 208 + 4x + 0 y or 4x = 24 or x = 6`
Equating atomic no
`90 = 82 + 2x - y or 90 = 82 + 2 xx 6 - y or y = 4`
Hence `6 alpha and 4 beta` particles will be emitted