Which physical quantity is measured in grams per milliliter (g/mL)?

• A. Mass
• B. Volume
• C. Density
• D. Temperature

Answer: (C)

g/mL is a unit used to express how much mass is contained in a given volume, which is density. Density is defined as mass per unit volume, so you calculate it as density = mass ÷ volume. For example, if a substance has 6 g of mass in 2 mL of volume, its density is 3 g/mL. This unit specifically pairs mass (grams) with volume (milliliters), conveying how tightly matter is packed. Temperature, by contrast, uses degrees (Celsius or Kelvin); volume uses milliliters or liters; mass uses grams. So g/mL uniquely describes density, the mass-per-volume property of a material.