In which of the following molecules, bonding is not taking place in excited state `:`

Options

A. `CH_(4)`
B. `BF_(3)`
C. `IF_(7)`
D. `PCl_(3)`

Answer

4

Explanation

`{:(C^(**)rarr1s^(2)2s^(1)2p^(3),,"4 unpaired electron ":." 4 bonds"),(B^(**)rarr1s^(2)2s^(1)2p^(2),,"3unpaired electron " :." 3 bonds"),(I^(**)rarr5s^(1)5p^(3)5d^(3),,"7 unpaired electron " :." 7 bonds" ),(Prarr3s^(2)3p^(3),,"3 unpaired electron ":." 3 bonds"):}`
`.^(**)` represent excited state