Question

Which parameters/variables/properties control the density of a substance? Please explain the relation.

Answer 1

density=mass/volume

so clearly density depends on the mass and volume of the substance. Now going into the less apparent factors

One factor affecting the density of a material is how concentrated the atoms are in a given volume. In some cases, materials made of atoms with a lower atomic weight have a greater density than those with a higher atomic weight, due to the atoms being more tightly packed. This is especially true for solids.

Non-standard conditions can result in a change of volume, affecting the density of the materials. Also, certain temperatures and pressures can result in a change the state of the matter, which also affects the density.

External pressure pushes the atoms or molecules closer together and increased temperature usually expands the volume of the material, pushing the molecules apart.

A change in the phase or state of a material usually results in a change in density.