Which term describes the amount of mass contained per unit volume?

• A. Density
• B. Viscosity
• C. Molarity
• D. Pressure

Answer: (A)

Verified step by step guidance

1. Understand the question is asking for a term that describes the amount of mass per unit volume.
2. Recall that density is defined as mass divided by volume, mathematically expressed as \(\text{Density} = \frac{\text{Mass}}{\text{Volume}}\).
3. Recognize that viscosity refers to a fluid's resistance to flow, molarity refers to moles of solute per liter of solution, and pressure is force per unit area, so these do not describe mass per volume.
4. Conclude that the correct term for mass per unit volume is density.
5. Therefore, the answer is 'Density' because it directly relates mass and volume in its definition.