Which among the following are having diamagnetic property ?
(i) `B_(2)` (ii)`N_(2)`
(iii) `O_(2)` (iv) `C_(2)`

Options

A. ii, iii
B. I, iv
C. ii, iv
D. I, ii

Answer

C

Explanation

MO configuration for
(a) `B_(2)` = (total electrons = 10)
`= sigma 1s^(2), sigma^(**),1s^(2),sigma2s^(2),sigma^(**)2s^(2),pip_(x)^(1)=pip_(y)^(1)`
The has two unpaired electrons and nature is paramagnetic
(b) `N_(2)` = (total electrons = 14)
`= sigma 1s^(2), sigma^(**),1s^(2),sigma2s^(2),sigma^(**)2s^(2),pip_(x)^(2)-pip_(y)^(2), sigma2p_(z)^(2)` .
The has no upaired electrons and nature is diamagnetic
(c) `O_(2)` = (toatl electrons = 16)
`= sigma1s^(2) , sigma^(**) 1s^(2),sigma^(2)s^(2),sigma^(**) 2s^(2),sigma2p_(z)^(2) = pip_(z)^(2)pi^(**) p_(x)^(1), pi^(**) p_(y)^(1)`
Thus has two unpaired electrons and nature is paramagnetic .
(d) `C_(2)` = (Total electrons = 12)
`= sigma1 s^(2), sigma^(**) 1s^(2), sigma2s^(2), sigma^(**)2s^(2), pi 2 p_(x)^(2) = pi2p_(x)^(2)`
Thus, has no unpaired electron and nature is diamagnetic ,
Hence (c) is the correct option (i.e.b.d).