Based on the periodic table shown above, elements in which of the following groups are the poorest conductors of electricity?

Non-metals in general are poor conductors of electricity.

The elements generally regarded as nonmetals are:

hydrogen (H)

In Group 14: carbon (C)

In Group 15: nitrogen (N), phosphorus (P)

Several elements in Group 16, the chalcogens: oxygen (O), sulfur (S), selenium (Se)

All elements in Group 17 - the halogens

All elements in Group 18 - the noble gases

Phosphorus, sulphur and chlorine are poor conductors as " the outer electrons are not free to move and carry charge because they are held strongly in covalent bonds."