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."

Alinear relationship would look like a straight line on the graph. it could have a positive negative or 0 slope. so it could be a line potentially going in any direction but it must be perfectly straight.

The car would move to the right with 150 n of force. the 150 n of force from friction and air resistance slows the car from moving to the right with 300 n of force.