Explain real and apparent expansion of a liquid with an experiment.

1. 1 · Define both. Real expansion: the actual increase in volume of the liquid. Apparent expansion: the increase seen without allowing for the container's expansion.
2. 2 · Draw the apparatus. [Diagram: flask with a narrow tube, coloured liquid, burner below, levels L₂, L₁ and L₃ marked]
3. 3 · Describe the experiment.
   • Mark the starting level L₁ and heat the flask.
   • The level falls to L₂ as the flask expands first.
   • The level then rises to L₃ as the liquid expands.
4. 4 · State the results. Apparent: L₃ − L₁. Container: L₁ − L₂. Real: L₃ − L₂. Real = apparent + container expansion.
5. 5 · Define the coefficients. γr and γa: real or apparent rise in volume per degree rise in temperature, per unit volume; unit K⁻¹; γr = γa + γv.
6. 6 · Real-life link. Oil in a brim-full bottle overflows in the sun; liquid thermometers use expansion.
7. 7 · Close in one line. So the real expansion of a liquid is always more than its apparent expansion.

Scoring tip: Mark L₁, L₂ and L₃ in the right order on the diagram. The line 'real = apparent + container expansion' is the key result.