This resource explores density, resistivity and electrical conductivity in the context of copper. Density and resistivity of materials are called bulk properties: their value doesn't depend on the size or shape of a particular sample - only on the material itself. When we say that copper is a heavier metal than aluminium, we are comparing their densities. In a similar way, when we say that copper is a better conductor than aluminium, we are comparing their resistivities. This e-source looks at calculating the density and resistivity of materials, which use similar mathematical methods.