Which instrument is used to determine the dry mass of sediment collected from runoff in the described activity?

Which instrument is used to determine the dry mass of sediment collected from runoff in the described activity?

• A. Balance scale
• B. Thermometer
• C. Ruler
• D. Graduated cylinder

Answer: (A)

Measuring the dry mass requires a tool that directly measures how much matter is present. A balance scale does this by weighing the sediment against known masses or a standard on the other pan, giving you its mass. After drying the sediment to remove water, you weigh it again to obtain the dry mass. Thermometers, rulers, and graduated cylinders measure temperature, length, and volume, respectively, not mass, so they aren’t suitable for determining dry mass.

Measuring the dry mass requires a tool that directly measures how much matter is present. A balance scale does this by weighing the sediment against known masses or a standard on the other pan, giving you its mass. After drying the sediment to remove water, you weigh it again to obtain the dry mass. Thermometers, rulers, and graduated cylinders measure temperature, length, and volume, respectively, not mass, so they aren’t suitable for determining dry mass.