Question

An element (X) belongs to fourth period and fifteenth group of the periodic table. Which one of the following is true regarding the outer electronic configuration of (X)?
It has:

• A. Partially filled d-orbital and completely filled s-orbital
• B. Completely filled s-orbital and completely filled p-orbital
• C. Completely filled s-orbital and half filled p-orbital
• D. Half-filled d-orbital and completely filled s-orbital

Answer 1

The correct option is C Completely filled s-orbital and half filled p-orbital

The element belongs to fourth period and fifteenth group of the periodic table is Arsenic (As).

The electronic configuration of $As$ is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^3$

So, the element (X) has completely filled s and d-orbitals and half-filled p-orbital.

Hence, option (c) is the correct answer.