Solved Sample Paper 3 — Question 15

(a) Given,

Atomic number = 8, hence, number of protons = number of electrons = 8

Mass number = 16, hence, number of protons + neutrons = 16

So, Number of neutrons = mass number - atomic number = 16 - 8 = 8

Hence, number of neutrons = 8

(b)

1. One proton is emitted:
   As the atomic number is given as 8, the number of protons will be also 8,

$_{8}^{16}\text{P} \longrightarrow \space _{7}^{15}\text{A} + _{+1}^{\enspace 1}\text{p}$

2. One β particle is emitted

$_{8}^{16}\text{P} \longrightarrow \space _{9}^{16}\text{B} + _{-1}^{\enspace 0}\text{e}$