(a) Describe the arrangement and movement of the particles in a liquid. [2]
(b) Name the change of state when a solid turns directly into a gas. [1]
(c) A purple crystal of potassium manganate(VII) is placed at the bottom of a beaker of water. After a few hours, the purple colour has spread throughout the water. Name the process that causes this. [1]
- (a) arrangement: (particles) close together / touching or irregular / random arrangement / no regular pattern (either for the mark)(1)
- (a) movement: particles move around each other / slide past each other / flow (accept move randomly; reject vibrate only; reject move freely and far apart)(1)
- (b) sublimation(1)
- (c) diffusion(1)
- Answer: (a) close together, random arrangement, moving past each other (b) sublimation (c) diffusion
- Examiner tip: For liquids, 'vibrate' alone scores nothing — you must say the particles slide or move past each other.