Brass contracts more than invar.
Brass expands when it cools down.
Invar and brass contract by equal amounts.
Invar contracts more than brass.
Increases the average speed of the water molecules
Increases the average separation of the water molecules
Raises the temperature of the air near the water
Splits the water molecules into their separate atoms
3 000 000 J / kg
50 000 J / kg
3000 J / kg
2000 J / kg
The quantity of heat required to raise the temperature of an object through 1 K
The quantity of heat required to raise the temperature of 1 kg of a substance through 1 K
The quantity of heat required to convert an object from solid to liquid without a change in temperature
The quantity of heat required to change 1 kg of a substance from solid to liquid without a change in temperature
Expands by the same amount as the tooth when heated.
Expands more than the tooth when heated.
Expands less than the tooth when heated.
Does not expand when heated.
To allow for expansion of the rail sections during hot weather
To allow for vibrations of the rail sections as the train passes over them
To allow rain water to drain from the rail sections
To keep the wheels of the train and carriages on the rail sections
The attraction between electrons and the nucleus
The attraction between the atoms in a molecule
The force between molecules
The force of gravity
It breaks the bonds holding the molecules together. Molecules escape from the liquid.
It breaks the bonds holding the molecules together. The solid becomes liquid.
It makes the molecules move faster but there is still a strong attraction between them.
It makes the molecules move faster and so the temperature rises.
The distance between the molecules increases, making the bar longer.
The molecules get larger, making the bar longer
The molecules vibrate more quickly, making the bar denser.
The speed of the molecules increases, making the bar thinner.
The gas expands.
The molecules get larger.
The piston remains in the same place.
The speed of the molecules decreases.