Final answer:
The correct measure of density is a. g/cm³. Density, generally expressed as mass per unit volume, is commonly used in the form of grams per cubic centimeter for solids and liquids in laboratory settings.
Step-by-step explanation:
The correct measure of density is a. g/cm³. Density is defined as mass per unit volume and is expressed as grams per cubic centimeter (g/cm³) for solids and liquids, and grams per liter (g/L) for gases. The SI unit of density is kilograms per cubic meter (kg/m³), but in practice, especially in laboratories, g/cm³ is commonly used because it is more meaningful for most people, as the density of water at room temperature is exactly 1 g/cm³. For example, if a material has a mass of 300 grams and occupies a volume of 100 cm³, its density is calculated as the mass divided by the volume, which in this case would be 3 g/cm³.