One way to describe how tightly packed the molecules are in a gas, liquid, or solid is in terms of \(\textit{density}\). The \(\textbf{density}\) of a substance, denoted by the Greek letter \(\rho\) (rho), is the mass of the substance divided by the volume that it occupies. The greater the density of a substance, the more kilograms of that substance are packed into a given number of cubic meters of volume: