Answer: has diffused more quickly, so it must be a
lighter gas. Its particles have greater velocity
than the particles of Y at the same temperature.
(Note though that they will both have the same
value for average kinetic energy.)
7 From the kinetic molecular theory we would
expect a solid to be more dense than its liquid,
and therefore that ice would sink in water.
8 Bubbles will be present through the volume
of the liquid. A brown gas is visible above the
brown liquid. As the two states are at the same
temperature, the particles have the same average
kinetic energy and are moving at the same
speed. The inter-particle distances in the gas are
significantly larger than those in the liquid.
9 At certain conditions of low temperature and low
humidity, snow changes directly to water vapour
by sublimation, without going through the liquid
phase.
10 Steam will condense on the skin, releasing energy
as it forms liquid at the same temperature (E–D
on Figure 1.4). This is additional to the energy
released when both the boiling water and the
condensed steam cool on the surface of the
Explanation:
