What is meant by the term bond order? Calculate the bond order of : `N_(2),O_(2),O_(2)^(+) and O_(2)^(-)`.

Explanation

Bond order is defined as the number of covalent bonds in a covalent molecule. It is equal to one half of the difference between the number of electrons in the bonding and antibonding molecular orbitals i.e.
`"Bond order"=({:("No. of electrons in"),("bonding M.Os."):}-{:("No. of electrons in"),("anti bonding M.Os."):})/(2)`
`N_(2):KK(sigma2s)^(2)(sigma^(**)2s)^(2)(pi2p_(x))^(2)(pi2p_(y))^(2)(sigma2p_(z))^(2)`
`"B.O"=(8-2)/(2)=3`
`O_(2):KK(sigma2s)^(2)(sigma^(**)2s)^(2)(sigma2p_(z))^(2)(pi2p_(x))^(2)(pi2p_(y))^(2)(pi^(**)2p_(x))^(1)(pi^(**)2p_(y))^(1)`
`"B.O"=(8-4)/(2)=2`
`O_(2)^(+):KK(sigma2s)^(2)(sigma^(**)2s)^(2)(sigma2p_(z))^(2)(pi2p_(z))^(2)(pi2p_(x))^(2)(pi2p_(y))^(2)(pi^(**)2p_(x))^(1)`
`B.O=(8-3)/(2)-2.5`
`O_(2)^(-):KK(sigma2s)^(2)(sigma^(**)2s)^(2)(sigma2p_(z))^(2)(pi2p_(x))^(2)(pi2p_(y))^(2)(pi^(**)2p_(y))^(2)(pi^(**)2p_(y))^(1)`
`B.O=(8-5)/(2)=1.5`