A student has two different liquids, liquid X and liquid Y. Liquid X has a greater mass than liquid Y, but both liquids occupy the same volume. State what is meant by density and explain which liquid has the greater density.

Cambridge International IGCSE Physics (0625) — 1.4 Density · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

Density is the mass per unit volume of a substance.
Liquid X has the greater density.
Because density = mass ÷ volume and both liquids occupy the same volume, the one with the greater mass must have the greater density.

Examiner tips

  • Define density as mass per unit volume. State which liquid has greater density. Explain that equal volumes mean the liquid with greater mass has greater density.
  • Use the formula density = mass/volume to justify your answer.

Common mistakes

  • Confusing density with mass or volume alone. Failing to mention that the volumes are equal. Using the wrong liquid as having greater density.

Mark scheme (4 marks)

  1. Density is the mass per unit volume (of a substance/object)
  2. Liquid X has a greater density than liquid Y
  3. Because density depends on mass divided by volume, and both liquids have the same volume
  4. Liquid X has greater mass (for the same volume), so its density is greater

Key terms in this question

density · mass · volume

Related

More Density questions

▶ Try answering this question with AI marking (free) →