Density describes how much mass is contained in a certain volume. knowing how far apart molecules are in each state, which best ranks solids, liquids, and gasses from least dense to most dense?

The order will be: gases < liquids < solids

Explanation:

Density is defined as measure of mass of substance present in unit volume of the substance.It is measured in gram per centimeter cube .

In solid state, molecules are strongly associated with each other that is they are tightly packed. Due to this tight packing, more mass will be present in a unit volume.

In liquid state, molecules are weakly associated with each other. Due to this weak association, the mass present in a unit volume will be less than that of the solid state.

In gaseous state, molecules are very far apart from each other. Due to this very weak association, the mass present in a unit volume will be less than that of the solid and the liquid state

So,the order from least dense to most dense will be:

Gases < liquids < solids

water is used to store them because it would keep the radiation from getting out in the open and causing harm to the workers