Question

A radioactive nucleus ‘A’ undergoes a series of decays according to the following scheme:



The mass number and atomic number of A are 180 and 72 respectively. What are these numbers for A 4 ?


Solution:


A has mass number as 180 and atomic number 172 .

Formation of A 1 by α-decay:



Formation of A 2 by β decay:



Formation of A 4 :

In r -decay, mass number and atomic number remain the same.

Thus,



Mass number of A 4 = 172

Atomic number of A 4 ­ = 169

some mistake kindly check....

Answer 1

Actually I know the answer but I am not sute

Answer 2

yes you are right... there's no mistake.