<Dl> <Dd> ρ = m V (\ displaystyle \ rho = (\ frac (m) (V))) </Dd> </Dl> <Dd> ρ = m V (\ displaystyle \ rho = (\ frac (m) (V))) </Dd> <P> where ρ is the density, m is the mass, and V is the volume . In some cases (for instance, in the United States oil and gas industry), density is loosely defined as its weight per unit volume, although this is scientifically inaccurate--this quantity is more specifically called specific weight . </P> <P> For a pure substance the density has the same numerical value as its mass concentration . Different materials usually have different densities, and density may be relevant to buoyancy, purity and packaging . Osmium and iridium are the densest known elements at standard conditions for temperature and pressure but certain chemical compounds may be denser . </P>

Which of the following units to measurement could be used to describe density