Question

if ADZ is parent atom and E is the daughter atom of an element write a balanced nuclear reaction to indicate an alpha particle emission

Answer 1

Let's consider element D with atomic number Z and mass number A. Then the reaction alpha particle emission is

$\displaystyle ^A_ZD \rightarrow ^{A-4}_{Z-2} E + ^4_2 He$

Upper left numbers are mass numbers, lower left numbers are atomic numbers. Both are conserved in nuclear reactions. One can check it directly from the equation - sum of Z and A is the same on the both sides of the equation.

Answer: $\displaystyle ^A_ZD \rightarrow ^{A-4}_{Z-2} E + ^4_2 He$