You might have observed in CO2 molecule that there are two pairs of valence electrons on each of the oxygen atoms that are not bonded. Such a pair of electrons is called a lone pair. Now how many lone pairs are present is S8 molecule?
16
The structure for S8 molecule is crown shaped. Each sulphur is bonded to 2 other sulphur atoms. The number of valence electrons in S8 is 6 out of which two are used in bonding with other sulphur atoms. Each sulphur is left with 2 lone pairs. For 8 sulphur atoms, there are 16 lone pairs.