Which instrument is used to measure an object's mass to a very high degree of precision?

• A. Pipette Filler-Dispenser
• B. Magnetic Stir Bar
• C. Pipetting Bulb
• D. Laboratory Balance

Answer: (D)

Measuring mass with high precision requires a device that can detect tiny differences in an object's weight against known masses, which a laboratory balance is designed to do. A laboratory balance provides very fine readings and can measure mass with great sensitivity, often down to milligrams or even micrograms depending on the model. The other tools are for handling liquids or mixing rather than measuring mass: a pipette filler-dispenser is used to fill pipettes, a magnetic stir bar to mix liquids, and a pipetting bulb to create suction for pipettes. None of these give precise mass readings, so the laboratory balance is the correct instrument for high-precision mass measurements.