Bond formation in Sodium Chloride (NaCl)
NaCl is an ionic solid.
The general electronic configurations are...
Na−1S22S22P63S1
Cr−1S22S22P63S23P5
Na is in excess of one electron to attain octet configuration.
Cl has one electron less to attain octet configuration.
So, the excess one electron is transferred to a chlorine atom from Na(sodium) atom and thus an ionic bond is formed due to the transfer of electrons. Chloride being a mole electronegative atom than sodium tends to attract the shared electron pair towards itself.
Thus NaCl has Na+ and Cl− atoms.
Na+−Cl−
Chloride attains octet configuration by gaining on the electron.
Sodium attains octet configuration by losing the electron.
Thus Ionic solid NaCl is stable.