Which of the following is the unit used to measure mass?

• A. Gram (g)
• B. Liter (L)
• C. Second (s)
• D. Meter (m)

Answer: (A)

Measuring how much matter an object has uses a mass unit. The gram is a unit of mass in the metric system, defined as one thousandth of a kilogram. The liter measures volume, the second measures time, and the meter measures length, so they describe different quantities. For larger masses, kilograms are used, but for the typical mass you’d encounter, the gram is the standard unit.