Asolid piece of lead has a mass of 23.94g and a volume of 2.10cm^3. from these data, calculate the density of lead in si units

A density of a substance is constant. It is an extensive property, meaning it does not depend on the amount of substance because it is a ratio of mass to volume. No matter how much of each there is, they would always have a fixed ratio called density. For lead, the density is

Density = mass/volume
Density = 23.94 g/ 2.10 cm³
Density = 11.4 g/cm³