Physical changes

Question 1

What are physical changes?

Answer 1

Something that changes a solid, liquid or gas into a solid, liquid or gas with no change of mass.

Question 2

What do solid particles look like?

Answer 2

Solids have a fixed shape and cannot flow because their particles are only able to vibrate about a fixed position. They cannot move from place to place.

Question 3

What do liquid particles look like?

Answer 3

Liquids can flow and take the shape of the bottom of their container because their particles can move over each other. For example, when water is poured into a glass, the particles of water move over each other and into the corners of the glass. The particles keep on moving over each other as the water takes the shape of the glass.

Question 4

What do gas particles look like?

Answer 4

Gases can flow to fill their container and to take its shape. This is because their particles can move in all directions. For example, when a Bunsen burner is connected to a gas tap and turned on, natural gas flows through the rubber tubing. The particles of natural gas are free to move anywhere inside the tubing, and pressure forces them through the tubing and into the Bunsen burner.

Question 5

What is the boiling point of water?

Answer 5

99.98 degrees Celsius.

Question 6

What is the melting point of water?

Answer 6

0.0 degrees Celsius

Question 7

Can you compress gases?

Answer 7

Yes

Question 8

What happens to a bar of steel when it is cooled down?

Answer 8

It gets shorter.

Question 9

In which state are atoms closest together (except water)?

Answer 9

solids

Question 10

In which state do atoms have the most energy?

Answer 10

gases

Question 11

What is the transition from a solid to a gas called?

Answer 11

Sublimation

Question 12

In which state is water most dense?

Answer 12

Liquid