What defines density of chemical substances?

[Stanley514]

What defines density of chemical substances at the same pressure and temperature?

 

[dextercioby]

What type of density are you talking about? Mass density?

 

[Stanley514]

What type of density are you talking about? Mass density?

Density of molecular substances is defined by forces of attraction and repulsion between its molecules. I wish to know why hydrogen molecules, for example, repulse each other much more than say, Lithium molecules.

 

[nasu]

Are you comparing the densities of gases or densities of condensed phases (solid, liquid)?

 

[SteamKing]

Density of molecular substances is defined by forces of attraction and repulsion between its molecules.

IDK about that. I always thought the density of a substance was defined by how much mass of the substance was contained in a unit volume. Can you provide another source for your definition of density?