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Which statement about evaporation is correct?
Evaporation causes the temperature of the remaining liquid to decrease.
Evaporation does not occur from a cold liquid near its freezing point.
Evaporation does not occur from a dense liquid, such as mercury.
Evaporation occurs from all parts of a liquid.
A gas is stored in a sealed container of constant volume. The temperature of the gas increases.
This causes the pressure of the gas to increase.
What happens to the gas molecules during this pressure increase?
The average kinetic energy of the molecules increases.
The average separation of the molecules decreases.
The average separation of the molecules increases.
The volume of each molecule increases.
A liquid is evaporating. The liquid is not boiling.
Which statement about the liquid is correct?
Any molecule can escape, and from any part of the liquid.
Any molecule can escape, but only from the liquid surface.
Only molecules with enough energy can escape, and only from the liquid surface.
Only molecules with enough energy can escape, but from any part of the liquid.
Air in a sealed syringe is slowly compressed by moving the piston. The temperature of the air
stays the same.
Which statement about the air is correct?
The pressure of the air decreases because its molecules now travel more slowly.
The pressure of the air decreases because the area of the syringe walls is now smaller.
The pressure of the air increases because its molecules now hit the syringe walls morefrequently.
The pressure of the air increases because its molecules now travel more quickly.
A substance loses thermal energy (heat) to the surroundings at a steady rate.
The graph shows how the temperature of the substance changes with time.
What could the portion PQ of the graph represent?
The same quantity of thermal energy is supplied to two solid objects X and Y. The temperature
increase of object X is greater than the temperature increase of object Y.
Which statement explains this?
X has a lower melting point than Y.
X has a lower density than Y.
X has a lower thermal capacity than Y.
X is a better thermal conductor than Y.
An engineer wants to fix a steel washer on to a steel rod. The rod is just too big to fit into the hole
of the washer.
How can the engineer fit the washer on to the rod?
Cool the washer and then place it over the rod.
Cool the washer and rod to the same temperature and then push them together.
Heat the rod and then place it in the hole in the washer.
Heat the washer and then place it over the rod.
The pressure of a fixed mass of gas in a cylinder is measured. The temperature of the gas in the
cylinder is then slowly increased. The volume of the cylinder does not change.
Which graph shows the pressure of the gas during this process?
The diagram shows four markings on a liquid-in-glass thermometer.
Which temperatures are the upper and lower fixed points?
upper 110, lower 0
upper 110, lower -10
upper 100, lower -10
upper 100, lower 0
The thermal capacity of solid Y is greater than that of solid Z.
What is a consequence of this?
Solid Y needs less thermal energy to melt it than solid Z.
Solid Y needs less thermal energy to raise its temperature by 1°C than solid Z.
Solid Y needs more thermal energy to melt it than solid Z.
Solid Y needs more thermal energy to raise its temperature by 1°C than solid Z.
In an experiment, a thermometer is placed in a test-tube of hot liquid. The temperature of the
liquid is recorded every half minute. The table shows the results.
What is the melting point of the substance?
The diagrams show four blocks of steel. The blocks are all drawn to the same scale.
The same quantity of thermal energy (heat) is given to each block.
Which block shows the greatest rise in temperature?
Evaporation occurs when molecules escape from a liquid surface into the air above it. During this
process the temperature of the liquid falls.
Why does the temperature of the liquid fall?
The molecules in the vapour expand because the pressure is less.
The molecules left in the liquid have more space to move around.
The molecules move more slowly when they escape into the air.
The molecules with the highest energies escape into the air.
A gas storage tank has a fixed volume. The graph shows how the temperature of the gas in the
tank varies with time.
At time Y, the gas molecules are
closer together than at time X.
hitting the sides of the tank harder than at time X.
larger in size than at time X.
moving more slowly than at time X.