NEET2026ChemistryChapterActual
Assertion (A): Oxygen molecule ( O₂ ) is paramagnetic in nature. Reason (R): The molecular orbital electronic configuration of O₂ contains two unpaired electrons in its bonding molecular orbitals.
Options
- ABoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
- BBoth Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
- CAssertion (A) is true but Reason (R) is false.
- DBoth Assertion (A) and Reason (R) are false.
Correct answer
C. Assertion (A) is true but Reason (R) is false.
Step-by-step solution
The total number of electrons in O₂ molecule is 16 . The molecular orbital electronic configuration of O₂ is _ 1s ² ^ * _ 1s ² _ 2s ² ^ * _ 2s ² _ 2p_z ² _ 2p_x ² = _ 2p_y ² ^ * _ 2p_x ¹ = ^ * _ 2p_y ¹ . Due to the presence of two unpaired electrons, O₂ is paramagnetic in nature. Thus, Assertion (A) is true. The two unpaired electrons are present in the antibonding molecular orbitals ( ^ * _ 2p_x and ^ * _ 2p_y ), not in bonding molecular orbitals. Thus, Reason (R) is false. Answer: Assertion (A) is true but Reason