States of Matter

Question 2

What are the particles in a solid like?

Answer 2

• particles vibrate about a fixed position
• particles cannot move very much
• bonds between atoms are strong (high density)

Question 3

What are the particles in a liquid like?

Answer 3

• bonds between particles are weaker, so they can move
• particles can flow to fill the shape of a container

Question 4

What are the particles in a gas like?

Answer 4

• particles move randomly in all directions
• there is no force of attraction between particles, so they are not very dense

Question 5

What is the difference between boiling and evaporation?

Answer 5

Boiling is when all particles have enough energy to change state into gases

Evaporation is where only particles on the surface have enough energy to change state into gases (e.g puddles evaporate)

Question 6

What is the process called when solids change state to liquids?

Answer 6

Melting

Question 7

What is the process called when liquids change state to gases?

Answer 7

Evaporation

Question 8

What is the process called where gases change state to liquids?

Answer 8

Condensation

Question 9

What is the process called when the liquids change state to solids?

Answer 9

Freezing

Question 10

What is the process called when solids change state into to gases?

Answer 10

Sublimation

Question 11

What is the process called when gases change state to solids?

Answer 11

Deposition

Question 12

Why would a less concentrated liquid of potassium permanganate seem more clear than a higher concentration liquid of potassium permanganate?

Answer 12

Because, in the less concentrated solution, there are less potassium permanganate particles therefore the colour is less prominent

Question 13

What is diffusion?

Answer 13

• The movement of particles from an area of higher concentration to an area of lower concentration
• particles will collide during this
• Particles in gases have a large store of kinetic energy, therefore can easily move and so they can diffuse. Particles in liquids have a smaller kinetic energy store, but their particles can still move, but not as much as gases because they have stronger bonds between particles. Particles in liquids can also diffuse, but not as quickly as gases.

Question 14

Which states are faster to diffuse?

Answer 14

The fastest are gases, then liquids and solids are impossible to diffuse as their particles cannot move

Question 15

What are the factors which affect the rate of diffusion?

Answer 15

• how much energy the particles have
• collisions with other particles
• the density/ mass of the substance (the smaller the atomic mass of an element, the lighter it is, so it can move and diffuse the fastest)
• the state of matter

Question 16

What is the name of solid crystals which can turn to purple vapour on heating without forming a liquid (sublime).

Answer 16

Iodine crystals

Question 17

What happens to the temperature of a substance whilst it changes state?

Answer 17

When a substance changes state, its temperature stays the same for a while

Question 18

Why can substances (e.g. bromine) travel faster in a vacuum than in the air

Answer 18

In the substance (e.g. bromine) particles keep bumping into air particles which slows the process down, in a vacuum nothing gets in the way.

Question 19

Why does disinfectant alcohol feel cold on the skin, even at room temperature?

Answer 19

Because, as the alcohol evaporates, heat is needed to break the attractions between the particles. This heat is taken from the skin.

Question 20

Describe an experiment to show that particles are very small

Answer 20

• 10ml cubed of potassium permanganate solution are added to 90 mL of water.
• The potassium permanganate crystals dissolve into a solution in the water
• 10ml of this solution is added to 90 mL of water. This is repeated until eventually you have a colourless solution
• Although it is mainly water, there are some potassium permanganate particles in the solution, but they are too small to be seen, therefore proving that particles are very small.

Question 21

In an experiment to test the diffusion of hydrogen chloride particles and ammonia particles in a test tube, where does the white ring form?

Answer 21

Near the middle, but closer to the hydrogen chloride particles