A chemical balance is used for measuring

Step 1: Analyze the question The question asks what quantity a chemical balance measures.

Step 2: Explain the concept A chemical (analytical) balance is a very sensitive instrument that works by comparing an unknown object with standard known masses. When the beam is level, the two sides are balanced. This works because weight is proportional to mass at the same location, so the masses on both pans are equal.

Step 3: Go through the options

• A. Volume: Measured with a measuring cylinder, burette, or pipette. A balance does not do this.
• B. Mass: A balance compares masses directly. This is correct.
• C. Thickness: Measured with a micrometer screw gauge or vernier calipers.
• D. Density: This must be calculated (density = mass ÷ volume), and it needs both a mass and a volume measurement. A balance gives only the mass part.

Step 4: Answer A chemical balance is used for measuring mass.

Exam tip: Match instruments to quantities:

• Balance → mass
• Measuring cylinder or burette → volume
• Micrometer screw gauge → small thickness or diameter
• Hydrometer → density of liquids

Remember that a balance measures mass, while a spring balance measures weight.