Question

Refer to the image of a lava lamp to answer the question.


In a lava lamp, a waxy substance rises and falls repeatedly. What causes the waxy substance to rise? Check all that apply.

The waxy substance is cold.
The waxy substance is warm.
The waxy substance is less dense than the surrounding liquid.
The waxy substance is more dense than the surrounding liquid.
Convection is occurring.

Answer 1

Select:
- The waxy substance is warm.
- The waxy substance is less dense than the surrounding liquid.
- Convection is occurring.

Explanation: the lamp's bulb heats the wax, so it becomes warmer and its density drops relative to the surrounding fluid. The buoyant difference makes the warmed blobs rise; they then cool, become denser, and sink again, producing convective circulation.