Question

The number of unpaired electrons in one molecule of liquid oxygen is

• A. 0
• B. 2
• C. 3
• D. 4

Hint:

Oxygen molecules (O$_2$) have 2 unpaired electrons, making them paramagnetic, which is a result of the molecular orbital theory.

Answer 1

The Correct Option is B

Step 1: Understand the molecular structure of oxygen.
Oxygen (O$_2$) has 8 electrons in its outermost shell, and each oxygen atom contributes 8 electrons, for a total of 16 electrons in the O$_2$ molecule.
Step 2: Apply the molecular orbital theory.
- According to the molecular orbital theory, oxygen molecules (O$_2$) have two unpaired electrons in the antibonding $\pi^$ orbitals. - These unpaired electrons result in the paramagnetic behavior of O$_2$.
Step 3: Apply to the options.
The number of unpaired electrons in one molecule of liquid oxygen is 2, so option (B) is correct.
Final Answer: \[ \boxed{2} \]