Unit 1

Question 1

Name the 3 states of matter:

Answer 1

Solid (s), Liquid (l) and Gas (g).

Question 2

Define the kinetic theory:

Answer 2

The kinetic particle theory is based on the idea that substances are made of tiny particles. Particles in the 3 states of matter are arranged differently and and are in constant motion. Particles in different states have different movement/energy.

Question 3

Name 4 properties of solids:

Answer 3

• They particles are tightly packed together
• The particles have low energy, they can only vibrate in position
• They have fixed volume and shape
• High density (closeness of particles)

Question 4

Name 4 properties of liquids:

Answer 4

• Particles slip and move against each other (this being the reason they adopt the shape of the container)
• Particles are held tightly together but have enough energy to move around
• Liquids have a fixed volume
• Less dense than solids, but much denser than gases

Question 5

Name 4 properties of gases:

Answer 5

• Low density
• Random motion of particles (they bounce off each other and collide with the walls of the container)
• Gases do not have fixed volume
• Highest energy

Question 6

Define interconvert:

Answer 6

The changing of state from one to another e.g liquid to solid

Question 7

Arrangement and movement of particles in a solid?

Answer 7

In a fixed pattern and vibrate in their fixed position

Question 8

Arrangement and movement of particles in a liquid?

Answer 8

Randomly arranged and slip/move around past each other to adopt the shape of the container

Question 9

Arrangement and movement of particles in a gas?

Answer 9

Randomly arranged and bounce/collide with each other and the walls of the container

Question 10

List the states of matter from lowest to highest energy:

Answer 10

Solid, liquid and gas

Question 11

What is a state change?

Answer 11

When one state changes to another state

Question 12

List 4 differences between evaporation and boiling:

Answer 12

Evaporation is natural -> boiling is not
Evaporation is slow -> boiling is much quicker
Evaporation occurs at the surface of a liquid -> boiling occurs over a large mass of liquid
Evaporation has no bubbling effect -> boiling has a bubbling effect

Question 13

Define the state changes of melting:

Answer 13

Solid -> Liquid

Question 14

Process of melting:

Answer 14

Melting requires heat energy, which is then transformed into kinetic energy, allowing the particles in the solid to move.

Question 15

When does melting occur?

Answer 15

At the melting point (m.p)

Question 16

Define the state changes of boiling:

Answer 16

Liquid -> Gas

Question 17

Process of boiling:

Answer 17

Heat energy is required to make gas bubbles below the surface of the liquid. Gas bubbles then escape through the surface of the water, allowing liquid particles to escape through the surface within the liquid.

Question 18

When does boiling occur?

Answer 18

At the boiling point (b.p)

Question 19

Define the state changes of freezing:

Answer 19

Liquid -> Solid

Question 20

Process of freezing:

Answer 20

Requires a significant drop in thermal energy and occurs at a specific temperature

Question 21

Define the state changes of evaporation:

Answer 21

Liquid -> vapour

Question 22

Process of evaporation:

Answer 22

Particles in a liquid can move around, and possess different amounts of energy, and the faster moving particles can escape from the surface of the liquid, turning into a gas state.

Question 23

What affects the speed of evaporation?

Answer 23

The temperature and how shallow/deep the liquid is.

Question 24

Define the state changes of condensation:

Answer 24

Gas -> liquid

Question 25

Process of condensation:

Answer 25

When a gas is cooled. Particles in a gaseous state lose energy, and when they collide with each other, they lack energy to bounce away, and bunch up to form liquid.

Question 26

Define the state changes of sublimination:

Answer 26

Solid -> gas

Question 27

What happens to the volume of a gas when the temperature rises?

Answer 27

The volume of the gas increases, however the density of the gas decreases.

Question 28

What happens when you add pressure to a gas in a container?

Answer 28

The pressure increases, which decreases the volume of the gas.

Question 29

How is pressure created in a can?

Answer 29

Gaseous particles contain kinetic energy, allowing them to move around, colliding with other particles and the walls of the container, which creates pressure.

Question 30

What happens to the gaseous particles when we increase the temperature?
Give an example of how we can see this:

Answer 30

They gain more kinetic energy, allowing them to travel faster, and collide with each other/the walls more frequently.
If the walls of the container are stretchy/flexible, we will see the material stretching, e.g. hot air balloon.

Question 31

What happens when there is a decrease in volume with a container of gas?

Answer 31

There will be an increase in pressure because the smaller volume gas particles have, the more frequently they collide with each other/the walls more frequently.

Question 32

What is diffusion?

Answer 32

Diffusion is the process different gases/liquids mix and due to their random motion of particles.

Question 33

How do particles move during diffusion?

Answer 33

They move from the area with the highest concentration to an area of low concentration.

Question 34

How can we speed up diffusion?

Answer 34

Increase the temperature.

Question 35

Does diffusion happen quicker with gases than liquids? if yes, explain why:

Answer 35

Yes, because the energy gaseous particles possess greater energy than liquid particles, allowing them to diffuse quicker.

Question 36

How does the weight of the gas particle affect the diffusion rate?

Answer 36

The lighter the gas particle, the quicker it can travel and the heavier the gas particle, the slower it can travel, meaning that the lighter the particles, the quicker diffusion rate it has.

Question 37

What do the periodic table group numbers represent?

Answer 37

They represent the number of electrons in the valence shell.

Question 38

What do the period numbers of the periodic table represent?

Answer 38

Number of electron shells.

Question 39

What is an element?

Answer 39

The substance with the same atoms, that have the same number of protons - and can’t be made any simpler

Question 40

What is a compound?

Answer 40

A substance made up of 2 or more elements, chemically combined

Question 41

What is mixture?

Answer 41

A mixture is a substance made up of 2 or more compounds or elements, that are not chemically combined

Question 42

Describe the structure of an atom.

Answer 42

Central nucleas contains neutrons and protons, surrounded by electrons in shells

Question 43

State the relative charges and relative masses of a proton, neutron and electron:

Answer 43

Proton: positive charge, 1 mass
Neutron : no charge, 1 mass
Electron: negative charge, 1/2000 mass (neglible)

Question 44

What is the proton/atomic number?

Answer 44

The number of protons in the nucleus of an atom

Question 45

What is mass number/nucleon number?

Answer 45

Total number of protons and neutrons in the nucleus of an atom

Question 46

What is an isotope?

Answer 46

Different atoms of the same element that have the same number of protons but different numbers of neutrons

Question 47

Why are isotopes from the same element?

Answer 47

They have the same chemical properties because they have the same number of electrons and therefore the same electronic configuration