C3

Question 1

Why are solids hard to compress?

Answer 1

• The particles are packed together in a regular pattern with no space between them
• Have a fixed shape and cannot flow from place to place

Question 2

Why can’t solids move from place to place?

Answer 2

The particles can vibrate but not move

Question 3

Why are liquids hard to compress?

Answer 3

Particles are close together with no space between them

Question 4

Why are gases easy to compress?

Answer 4

The particles in a gas are widely spread and fill the spaces of the container

Question 5

How do gases move?

Answer 5

Quickly and randomly

Question 6

How can you change the state of a substance?

Answer 6

Putting in or taking out energy

Question 7

What do you have to do to convert a solid to a liquid?

Answer 7

Put energy in as the particles in a liquid move. The energy is used to break the forces of attraction

Question 8

What does stronger the forces of attraction mean?

Answer 8

More energy needed to break them and higher the melting point

Question 9

Why do substances have low boiling points?

Answer 9

Have low forces of attraction

Question 10

How do you turn gas into a liquid?

Answer 10

Condense

Question 11

What are the limitations of the simple particle model?

Answer 11

• All particles are solid spheres
• No forces between particles

Question 12

Why do elements react?

Answer 12

To form a full outer energy level

Question 13

What is ionic bonding?

Answer 13

When a metal reacts with a non metal

Question 14

What do ionic compounds form?

Answer 14

Giant structures

Question 15

What are giant ionic lattices?

Answer 15

When negative ios are surrounded by positive ions

Question 16

What are electrostatic forces?

Answer 16

Giant ionic lattices have strong forces of attraction between positive and negative ions

Question 17

What are ionic bonds?

Answer 17

Electrostatic forces that hold negative and positive ions together

Question 18

Facts about ionic compounds?

Answer 18

• Have high melting and boiling points
• Cannot conduct electricity when solids

Question 19

Why do ionic compounds have high melting and boiling points?

Answer 19

The electrostatic forces require a lot of heat energy to break

Question 20

Why can’t ionic compounds conduct electricity?

Answer 20

Ions cannot move and locked in strong electrostatic forces of attraction

Question 21

When can ionic compounds conduct electricity?

Answer 21

Melted or dissolved in water (the ions can move and carry the charge)

Question 22

What are facts about ionic compounds?

Answer 22

• Form giant structures where every positive ion is surrounded by negative ions
• Giant ionic lattices have strong forces of attraction (electrostatic forces)

Question 23

What is covalent bonding?

Answer 23

Sharing electrons

Question 24

When does covalent bonding happen?

Answer 24

Between non metal elements

Question 25

Properties of small covalent molecules?

Answer 25

Have low melting and boiling points (usually gases or liquids at room temp)

Question 26

Why do small molecules have low melting and boiling point?

Answer 26

- atoms are held by strong covalent bonds - Very weak forces between intermolecular forces

Question 27

What does intermolecular mean?

Answer 27

Betwen forces

Question 28

Why do small covalent bonds have low melting and boiling points?

Answer 28

Weak intermolecular forces and does not require a lot of energy to break

Question 29

Why is it when alkanes get larger the boiling point increases?

Answer 29

The intermolecular forces increase and require more energy

Question 30

Why do small covalent molecules not conduct electricity?

Answer 30

Molecules do not have an overall electric charge

Question 31

Facts about giant covalent molecules?

Answer 31

Always solid at room temperature

Question 32

Why do giant covalents always have high melting and boiling points?

Answer 32

Millions of strong covalent bonds

Question 33

How is diamond formed?

Answer 33

From carbon

Question 34

How is diamond formed?

Answer 34

Each carbon atom forms 4 strong covalent bonds

Question 35

Why does diamond have a high melting point?

Answer 35

It has a lot of carbon covalent bonds so requires a lot of energy

Question 36

Why can't diamond conducts electricity?

Answer 36

No free electrons to carry out electrical charge

Question 37

Why does silicone dioxide have a high melting and boiling point?

Answer 37

Huge number of strong covalent bonds must be broken and requires energy

Question 38

Graphite properties?

Answer 38

- High melting and boiling point - Soft and slippery - Great conductor for electricity and heat

Question 39

How is graphite formed?

Answer 39

Element carbon and forms 3 covalent bonds from hexagonal rings

Question 40

Why does graphite have a high boiling and melting point?

Answer 40

Has strong covalent bonds

Question 41

Why is graphite slippery?

Answer 41

No covalent bonds between layers so they can slide

Question 42

What can delocalised electrons do?

Answer 42

Conduct heat and electricity

Question 43

Why is graphite not a metal?

Answer 43

Based on element carbon

Question 44

Why is graphite a good conductor to heat and electricity?

Answer 44

Have delocalised electrons which can move

Question 45

What is graphene?

Answer 45

A single layer of graphite One atom thick

Question 46

Graphene properties?

Answer 46

- Good conductor of electricity - Very strong

Question 47

Why is graphene a good conductor of electricity?

Answer 47

It has delocalised electrons

Question 48

What are fullerenes?

Answer 48

Molecules of carbon atoms with hollow shapes

Question 49

How are fullerenes formed?

Answer 49

Hexagonal rings of carbon atoms

Question 50

Whats c60?

Answer 50

Buckminsterfullerene

Question 51

What are the uses of fullerenes?

Answer 51

- Pharmaceutical delivery - Lubricants - Catalysts

Question 52

Carbon nanotubes properties?

Answer 52

- High strength and can be stretched - Excellent conductors of heat and electricity

Question 53

Uses of carbon nanotubes?

Answer 53

Reinforce materials eg tennis rackets

Question 54

How are polymers made?

Answer 54

Joining thousands of small identical molecules

Question 55

What are monomers?

Answer 55

Alkene molecules

Question 56

Why are most polymers solids at room temperature?

Answer 56

The intermolecular forces between polymers are strong

Question 57

What are the electrons on the outer energy level of a metal?

Answer 57

Delocalised

Question 58

Whats between the sea delocalised electroms and positive metal ions?

Answer 58

Strong electrostatic attraction

Question 59

Whats a metallic bond?

Answer 59

Electrostatic bond in metals

Question 60

Why are metals great conductors of heat?

Answer 60

- Delocalised electrons can move - Charged metals carry electricity

Question 61

Why can metals be bent and shaped?

Answer 61

Able to slide over each other

Question 62

Metal properties?

Answer 62

- Bent and shapes - Good heat and electricty conductors

Question 63

What is an alloy?

Answer 63

A mixture of metals

Question 64

How are alloys harder than metals?

Answer 64

Different sizes of atoms distorts the layers making it harder to slide over

Question 65

What is a micrometer?

Answer 65

1 x 10-6

Question 66

What is a nanometer?

Answer 66

1 x 10-9

Question 67

Coarse particle diameter?

Answer 67

1x10-5 and 2.5 x 10-6

Question 68

What is the diameter of nano particles?

Answer 68

1 -100 nanometeres Contain few hundred atoms

Question 69

What happens when particle size decreases 10 times?

Answer 69

SA - VR increases 10 times

Question 70

Uses of nanoparticles?

Answer 70

- Medicines - Suncreams - Cosmetics - Deodrants - Electronics - Catalysts

Question 71

Risks of nanoparticles?

Answer 71

- can be absorbed by our body and enter our cells - No one knows long term effects