The particles in solid, liquid and gas are always vibrating.

• True

• False

When heated, particles ____ energy, and vibrate ____ vigorously. The distance between particles _________.

• lose, less, increases

• gain, more, decreases

• gain, more, increases

• lose, less, decreases

When cooled, particles ____ energy, and vibrate ____ vigorously. The distance between particles _________.

• lose, less, increases

• gain, more, decreases

• gain, more, increases

• lose, less, decreases

Cold air is more dense than hot air.

• True

• False

Why does the temperature stay constant during freezing?

• Heat energy absorbed is used to overcome very strong forces of attraction between solid particles

• Heat energy is released as the particles overcome strong forces of attraction to form a solid

• Heat energy is released as the particles move closer to each other to form a solid

• Heat energy is absorbed as the particles move closer to each other to form a solid

Why does the temperature stay constant during boiling?

• Heat energy is absorbed as the particles move closer to each other to form a gas

• Heat energy is released as the particles overcome strong forces of attraction to form a gas

• Heat energy absorbed is used to overcome strong forces of attraction between liquid particles

• Heat energy is released as the particles move closer to each other to form a gas

Why does a substance expand when heated?

When a liquid is heated it expands. Which statement is true about the particles?

• The size of particles increases.

  Distance between particles increases.

• The size of particles increases.

  Distance between particles does not change.

• The size of particles does not change.

  Distance between particles does not change.

• The size of particles does not change.

  Distance between particles increases.

When a substance is heated, its mass changes but its volume remains unchanged.

• True

• False

Using the particulate theory of matter, explain what happens to a substance during melting.