Question

6. Atoms of two elements P and Q have 5 electrons
in the second and third shells, respectively. What
could be the geometrical representations of P
and Q? What will the atomic numbers of these
elements be?​

Answer 1

Answer: P has atomic number 7, and Q has atomic number 15.

Explanation:

Electronic configuration of P= 2,5 (duplet rule) and of Q = 2,8,5 (Octet rule)

Thus, by adding the number of electrons, the atomic number can be calculated.