Assertion : `O_(2)` molecule is diamagnetic while `C_(2)` molecule is paramagnetic in nature.
Reason : Bond order of `O_(2) ` molecule is `1.5` and that of `C_(2)` molecule is `2.5` .

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason in not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Answer

D

Explanation

`O_(2) : (sigma1 s)^(2) (sigma**1s)^(2) (sigma2s)^(2) (sigma**2s)^(2) (sigma2p_(z))^(2)(pi2p_(x)^(2) = pi 2p_(y)^(2))(pi^(**)2p_(x)^(1) = pi^(**)2p_(y)^(1))`
Bond order ` = 1/2 (N_(b) - N_(a)) = 1/2 (10 - 6) = 2`
It contains two unpaired electrons hence it is paramagnetic in nature.
`C_(2) : (sigma 1s)^(2) (sigma^(**)1s)^(2) (sigma2s)^(2)(sigma^(**)2s)^(2) (pi 2p_(x)^(2) = pi 2p_(y)^(2))`
Bond order ` = 1/2 (8 - 4) = 2`
All electrons are paired hence it is diamagnetic in nature.