What is the main difference between the gas water vapor and the liquid water?

Question

A.
The molecules of water vapor are much smaller than those of liquid water.
B.
The molecules of water vapor pull on each other much more strongly than the molecules of liquid water do.
C.
Liquid water is made out of different molecules than water vapor is.
D.
Liquid water has much less space in between its molecules than water vapor does.

Answer 1

The main difference between gas water vapor and liquid water is:

D. Liquid water has much less space in between its molecules than water vapor does.

In a gas like water vapor, the molecules are much farther apart and move freely, while in liquid water, the molecules are closer together and have stronger intermolecular forces acting between them, resulting in a denser state.