Question

How many orbitals are singly occupied in $O_2$ molecule?

• A. 2
• B. 1
• C. 3
• D. 4

Answer 1

The correct option is A 2

Meaning of singly occupied orbital is that how many orbitals have only one electrons, Here is the electronic configuration of $O_2$ molecule:

$\left(\sigma 1s^2\right)(\sigma \ast 1s^2)\left(\sigma 2s^2\right)(\sigma \ast 2s^2)\left(\sigma 2p_z^2\right)(\pi 2p_x^2=\pi 2p_y^2)(\pi \ast 2p_x^1=\pi \ast 2p_y^1)$

It is clear from here that 2 orbitals $(\pi \ast 2p_x^1=\pi \ast 2p_y^1)$ have single electron.

So the correct option is $\left[A\right]$.