Review

When you heat a sample of a SOLID, the sample gets a little bigger. What happens to the particles of SOLID?

• Get bigger

• Loose mass

• Move faster

• Slow down

Most parents put a cold compress or a wet towel on the forehead of their child with fever. How does it help the child with his condition?

• The particles of water in the towel will absorb heat from the skin for evaporation.

• The low temperature of the wet towel will provide comfort for the child to sleep better.

• The water particles will prevent further loss of water in the child for faster recovery.

• The water from the towel will be absorbed by the skin, thus preventing dehydration.

The three common states of matter

When you remove energy from particles they move ________ and the matter contracts

When you add energy to matter, the particles move _______ and the matter expands.

When you bring two drops of water near each other and allow them to touch, they combine immediately and become one drop. Which of the following BEST explains this observation?

• Water molecules are made up of atoms.

• Water molecules are magnetic.

• Water molecules are a compound.

• Water molecules are attracted to each other.

When you heat a sample of a solid, the sample gets a little bigger. Which of the following BEST explains this observation?

• The particles move faster and get a little further apart.

• The heat helps the particle grow.

• Heating the sample makes it lighter.

• Heating helps the particles slide past each other.

A drop of ink is added to the water, and after some time, the ink spread throughout even without stirring. Which of the following statements best explains this observation?

• The movement of the particles of water facilitated the spread of ink molecules in the entire bottle.

• The ink spread in water because the particles of ink move to fill up spaces between the particles of water.

• The particles of ink and water moved and as a result of their interaction, the ink was uniformly scattered in water.

• Ink particles were pulled down by gravity and as they descend into the container, they diffused with the particles of water.

Which of the following explains how melting occur?

• Cooling water in the freezer until the water becomes solid.

• Heating a block of ice until the ice turns to water.

• Heating a pan of water until the water is all gone.

• Stirring some sugar in water until you cannot see the sugar.

A beaker with water and the surrounding air are all at 24°C. After ice cubes are placed in the water, which of the following will heat be transferred?

• The ice cubes in the air.

• The beaker to the air.

• The water to the ice cubes.

• The water to the beaker.