Question

Write down the atomic number of P, Q, R and S.

Answer 1

Answer:

z=A-N(No. of neutrons)

Explanation:

p- z=12-6 = 6

q-z=20-10 = 10

r-z=23-12 = 11

s- z = 25-18= 7

Answer 2

Answer:

The atomic numbers of four elements P, Q, R and S are 6, 8, 14 and 16 respectively. Out of these, the element known as metalloid is R having atomic no. 14 which is silicon.