In the reaction represented by,
`""_(Z)""^(A)Xto.""_(Z-2)""^(A-4)Yto.""_(Z-2)""^(A-4)Yto.""_(Z-1)""^(A-4)K`
the decays in the sequence are a)`alpha,beta,gamma` b)`beta,gamma,alpha` c)`gamma,alpha,beta` d)`alpha,gamma,beta`

Options

A. `alpha, beta,gamma`
B. `beta, gamma, alpha`
C. `gamma, alpha, beta`
D. `alpha, gamma, beta`

Answer

D

Explanation

In the first decay, mass number decreases by 4 and charge number decreases by 2. Prouct must be `alpha`.
In `2^("nd")` decay, no charge in A and Z shows that product must be `gamma.` In `3^("rd")` decay, charge number increases by 1. The product must be b`beta`