Tiny smoke particles are suspended in air inside a glass cell. When illuminated and observed through a microscope, they are seen to move.
Describe this movement.
Explain this movement in terms of air molecules and the smoke particles.
A student spills a small amount of propanone (acetone) on their hand. Propanone evaporates very rapidly at room temperature.
State whether the student's hand experiences heating, cooling, or neither at the site where the propanone is spilled. Explain your answer.
State any effect on the rate of evaporation of the propanone if a fan blows air across the student's hand.
151 exam-style questions on CIE IGCSE Physics 2.1.2a Particle structure and motion in solids, liquids and gases. Each one has a worked solution and a mark scheme showing where the marks go.