For questions involving (theoretical or experimental) comparison of density of elements or substances, calculating density of solutions, effects of temperature on density, and other chemical aspects of density.

Density (volumetric mass density) is defined as the mass per unit volume of a substance. Questions about density on this site will usually involve (theoretical or experimental) comparison of density of different elements or substances, calculating density of solutions, affect of temperature on density, and other chemical aspects of density.

Though, the concept of density is much more popular in Physics. Hence, questions involving density alongside involve buoyant forces, pressure, and other mechanical physics concepts, are better suited for Physics.SE instead (and will be closed as off-topic on Chem.SE)

history | excerpt history