Sec 3 Combined Science (Physics) Kinetic Particle Model topical questions

Name the three states of matter and state one property that distinguishes a gas from a solid.

Describe the motion of the particles in a solid.

State what happens to the average kinetic energy of the particles when a substance’s temperature rises.

Name the change of state when (a) a liquid becomes a gas at its boiling point, (b) a gas becomes a liquid.

Using the particle model, explain why solids have high densities and are almost incompressible, while gases have very low densities and are easily compressed.

A beaker of water is heated from 25 °C to 80 °C. Explain, in terms of particles, what the temperature rise means.

Explain why the temperature of a liquid stays constant while it boils, even though it is still being heated.

Substance X melts at 55 °C and boils at 120 °C. State the physical state of X (or the mixture) at: (a) 40 °C, (b) 55 °C while melting, (c) 90 °C, (d) 130 °C.

Steam at 100 °C and boiling water at 100 °C are at the same temperature, yet a steam scald is usually worse. Explain, using internal energy, why.

Ice is taken from a freezer at −18 °C and left in a warm room. Describe and explain, in terms of particles and energy, what happens (a) before the ice starts melting, (b) while it melts, (c) after it has all melted and the water warms to room temperature.

A student claims that "gases must be weightless because they have no fixed shape or volume". (a) Explain why the claim is wrong using the particle model, and suggest how the mass of the air in a sealed flask could be demonstrated. (b) Describe the arrangement, separation and motion of gas particles.

Explain, using the kinetic particle model: (a) why a solid expands slightly when heated but keeps its shape; (b) why a gas always spreads to fill its entire container; (c) why neither a solid nor a liquid is noticeably compressed by large forces.