Structure of Atom · Question 58

If a abX species emits first a positron, then two and two particles and in the last, one is also emitted and gets converted to cdY species. So correct relation is

1. c = a - 12, d = b - 5
2. c = a - 5, d = b - 1
3. c = a - 6, d = b - 0
4. c = a - 4, d = b - 2

Answer

(1) c = a - 12, d = b - 5

Solution

Change in mass number and atomic number for each emission:

Positron ( 0+1e): mass number 0, atomic number -1

Two ( 42He): mass number -8, atomic number -4

Two ( 0-1e): mass number 0, atomic number +2

One : mass number -4, atomic number -2

c = a - 8 - 4 = a - 12

d = b - 1 - 4 + 2 - 2 = b - 5

Answer: (1)