Number of neutrons i8n a parent nucleus `X`, which gives `""_(7)^(14)N` after two sucessive `beta-` emission would be:

Options

A. 9
B. 6
C. 7
D. 8

Answer

A

Explanation

After emitting a `beta`particle atomic number is increased by one unit and atomic weight has no change .So the atomic number of parent nucleus
`5^(x^(14))overset(-beta)rarr_(6)Y^(14)overset(-beta)rarr_(7)^(14)`
Number of neutrons =mass number -number of protons