Do you think that each sample occupies

Each sample (even gas) will occupy space. It all depends at the state of matter it is in. 
A solid will occupy a space, and the mass (A powder in a beaker, it will change its mass too)
A gas will occupy volume, a balloon is a good example
A liquid will most take up space and effect volume.

Temperature will affect these variables. Pressure will affect the space taken (Volume) of a gas temperature will affect this as well.  

30litre of li2o is 1.0002mole approximately 1 mole