Explain why nh3 has stronger intermolecular forces of attraction than cl2

NH3 has  stronger intermolecular forces compared to Cl2, due to NH3 having polar molecules, and hydrogen bonding.

Explanation:

There are three types of intermolecular forces:

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.