C3.1 - States Of Matter (Finished)

Question 1

What are the three states of matter?

Answer 1

Solids, liquids, gases

Question 2

What does the particle theory describe?

Answer 2

• The movement of particles

- The average distance between particles

Question 3

What theory explains the properties of solids, liquids and gasses?

Answer 3

The particle theory

Question 4

How are particles in a solid arranged?

Answer 4

There are strong forces of attraction between particles in solids which brings them close together and in a fixed position to form a lattice arrangement

Question 5

Particles in solids don’t move making solids keep a ______ shape and _______. However the particles ______ about their positions.

Answer 5

Definite, volume, vibrate

Question 6

Why do solids expand slightly when heated?

Answer 6

The hotter a solid becomes the more it’s particles vibrate

Question 7

Describe the arrangement particles in a liquid

Answer 7

They have weak forces of attraction between them, are randomly arranged and free to move past each other. They tend to stick closely together.

Question 8

Is a liquids shape and volume definitive?

Answer 8

Liquids have a definitive volume but not a definitive shape

Question 9

Describe the particles In a gas

Answer 9

In gasses particles are free to move around (as the forces of attraction between them is very weak) and are far apart. They travel in straight lines constantly with random motion.

Question 10

What happens to the particles of a gas when it is heated?

Answer 10

They move faster and either expand or their pressure increases

Question 11

Do gases keep a definitive shape or volume?

Answer 11

No

Question 12

What is the pressure of a gas caused by?

Answer 12

It is caused by the particles colliding with the sides of a container. The more frequent and energetic the collisions the higher the pressure of the gas

Question 13

How do state changes from solid to liquid happen?

Answer 13

1) Heat gives particles more energy
2) This makes the particles vibrate more, weakening the forces holding them together
3) At a certain temperature called the melting point the particles have enough energy to break free from their positions

Question 14

How do state changes from liquid to gas happen?

Answer 14

1) Heat gives particles more energy
2) This makes the particles vibrate more, weakening and breaking the bonds that hold them together
3) At a certain temperature called the boiling point the particles have enough energy to break their bonds and become a gas

Question 15

What is it called when a liquid turns into a solid?

Answer 15

Freezing

Question 16

How do state changes from gas to liquid happen?

Answer 16

1) As a gas cold, the particles no longer have enough energy to overcome the forces of attraction between them
2) Bonds form between the particles
3) At the boiling point so many bonds have formed between the gas particles that it becomes a liquid
4) This is called condensing

Question 17

What does the amount of energy needed for a substance to change state depend on?

Answer 17

How strong the forces between the particles are

Question 18

What happens to the temperature of a substance as you heat it beyond its melting point?

Answer 18

The temperature stops rising when the melting point is reached and only continues after it has been passed

Question 19

Why does temperature stop changing as a substance is changing state When melting/boiling?

Answer 19

The energy being transferred to the substance is being put into breaking the bonds between it’s molecules rather than increasing temperature

Question 20

What are some limitations of the particle model?

Answer 20

The particle model assumes particles are solid spheres with no forces between them. But these particles are molecules or ions, vary in size, are not always spherical and are mostly empty space