Which molecule/ion out of the following does not contain unpaired electrons?

Options

A. `N_(2)^(+)`
B. `O_(2)`
C. `O_(2)^(2-)`
D. `B_(2)`

Answer

C

Explanation

`N_(2)^(+) = KK sigma_(2s)^(2) sigma_(2s)^(**2) pi_(2_(p_(x)))^(2) pi_(2_(p_(y)))^(2) sigma_(2_(p_(z)))^(1)`
`O_(2) = KK sigma_(2s)^(2) sigma_(2s)^(**2) sigma_(2p_(z))^(2) pi_(2_(p_(x)))^(2) pi_(2_(p_(y)))^(2) pi_(2_(p_(x)))^(**1) pi_(2_(p_(y)))^(**1) `
`O_(2)^(2-) = KK sigma_(2s)^(2) sigma_(2s)^(**2) sigma_(2p_(z))^(2) pi_(2_(p_(x)))^(2) pi_(2_(p_(y)))^(2) pi_(2_(p_(x)))^(**2) pi_(2_(p_(y)))^(**2) `
`B_(2) = KK sigma_(2s)^(2) sigma_(2s)^(**2)pi_(2_(p_(x)))^(1) pi_(2_(p_(y)))^(1) `
thus , `O_(2)^(2-)` has no unpaired electrons.