Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GCSE Chemistry > Topic 2 - Bonding, Structure and the Properties of Matter > Flashcards

Topic 2 - Bonding, Structure and the Properties of Matter Flashcards

1
Q

Why are ions formed?

A

Because atoms are always trying to get a full outer shell to become more stable.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 3 types of chemical bonding?

A

There are three types of strong chemical bonds: ionic, covalent and metallic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What kind of compounds does ionic bonding occur in?

A

Metals and non-metals => electrons transferred from metal atoms to non-metal atoms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What kind of ions do metals become?

A

Positive ions, because they lose electrons to gain a full outer shell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What kind of ions do non-metals become?

A

Negative ions, because they gain electrons to gain a full outer shell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What holds ions together?

A

Strong electrostatic attraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What do the ions produced by metals in Groups 1 and 2 and by non-metals in Groups 6 and 7 have the electronic structure of?

A

The ions produced by metals in Groups 1 and 2 and by non-metals in Groups 6 and 7 have the electronic structure of a noble gas (Group 0).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What can the electron transfer during the formation of an ionic compound be represented by?

A

The electron transfer during the formation of an ionic compound can be represented by a dot and cross diagram.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is an ionic compound, structurally and how are they held together?

A

An ionic compound is a giant structure of ions (giant ionic lattice). Ionic compounds are held together by strong electrostatic forces of attraction between oppositely charged ions. These forces act in all directions in the lattice and this is called ionic bonding.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What can the structure of ionic compounds be represented by? (3)

A
  • Dot and cross diagram
  • 3D models
  • Ball and stick model
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the pros and cons of dot and cross diagrams to represent ionic compounds?

A

+ useful for showing how they’re formed
- don’t show structure of compound, relative size of ions or how they’re arranged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the pros and cons of 3D models to represent ionic compounds?

A

+ show relative sizes of ions, and regular patterns in ionic crystals
- only show outer layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the pros and cons of ball and stick models to represent ionic compounds?

A

+ show regular pattern, how ions are arranged and sometimes the relative size
- sometimes not shown to scale, and suggests there are gaps between ions when there isn’t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the main properties of ionic compounds? (4)

A
  • High m.p and b.p => large amount of energy to overcome the strong electrostatic attraction between the ions and to break the bonds
  • Most dissolve in water
  • Don’t conduct electricity when solid as the electrons are in fixed positions
  • When melted or dissolved, they can conduct electricity as electrons can move more freely
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When are covalent bonds formed?

A

When atoms share pairs of electrons, they form covalent bonds, between non-metals and non-metals. These bonds between atoms are strong.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why does covalent bonding happen?

A

So the outer shells of electrons can be more full and stable.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How can covalent bonds be represented? (4)

A
  • Dot and cross diagrams
  • Displayed formulas
  • 3D models
  • Ball and stick models
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are simple covalent bonds with 8 examples?

A

Made up of only a few atoms joined by covalent bonds. E.g, hydrogen, chlorine, hydrogen chloride, methane, ammonia, water, nitrogen + oxygen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the features of simple covalent molecules? (3)

A
  • Never conduct electricity
  • Low m.p and b.p, because they are mostly gases and liquids at room temp
  • Even though covalent bonds are strong, simple molecules have weak intermolecular forces which are easy to break as they need less energy to do so
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are polymers?

A

Consist of lots of long molecules made up of repeating sections. They can contain up to millions of atoms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the main features of polymers? (2)

A
  • Higher m.p and b.p because intermolecular forces are stronger than those in simple molecules, but still weaker than ionic or giant covalent compounds so the m.p and b.p still aren’t that high.
  • Solids at room temp.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are giant covalent structures?

A

Similar to giant ionic lattices, but no charged ions. All the atoms are bonded together with covalent bonds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the main feature of giant covalent structures?

A

They have very high m.p and b.p because they need to overcome strong covalent bonds, which takes a lot of energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the 3 allotropes of carbon?

A
  • Diamond
  • Graphite
  • Graphene
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the features of diamond? (3)

A
  • Each atom is connected to 4 other carbon atoms
  • Very high m.p + b.p
  • Doesn’t conduct electricity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the features of graphite? (6)

A
  • Each atom is connected to 3 other carbon atoms
  • Creates sheets of atoms arranged in hexagons (layers)
  • Layers are held together by weak intermolecular forces
  • Soft and slippery so good lubricant
  • Delocalised electrons between layers means layers can slide over one another + conduct electricity (1spare electron from each atom)
  • High m.p + b.p
27
Q

What are the features of graphene? (5)

A
  • Single layer of graphite
  • Very strong
  • Incredibly light => can be added to composite materials to improve strength without extra weight
  • Contains delocalised electrons => can conduct electricity
  • Has the potential to be used in electronics
28
Q

What are fullerenes?

A

Hollow molecules of carbon, shaped like tubes or balls.

29
Q

What are the 5 main uses of fullerenes?

A
  • In medicine
  • As catalysts
  • As lubricants
  • Strengthening materials
  • In electronics
30
Q

How can fullerenes be used in medicine?

A

Used to ‘cage’ other molecules. Used to deliver a drug to where its needed in the body.

31
Q

How can fullerenes be used as catalysts?

A

Large surface areas means they are good industrial catalysts.

32
Q

How can fullerenes be used as lubricants?

A

Coating of fullerenes reduces frictions, in machines and one day artificial joints.

33
Q

How can fullerenes be used to strengthen materials?

A

High tensile strength means they don’t break when stretch - so can strengthen things without much extra weight.

34
Q

How can fullerenes be used in electronics?

A

They are so small, that they can be used in small electrical circuits.

35
Q

What do metals consist of?

A

Metals consist of giant structures of atoms arranged in a regular pattern. The electrons in the outer shell of metal atoms are delocalised and so are free to move through the whole structure, as they aren’t associated with a particular atom/ bond.

36
Q

How does metallic bonding work?

A

The sharing of delocalised electrons gives rise to strong metallic bonds, between + metal ions and - metal ions.

37
Q

What are the features of pure metals? (4)

A
  • High m.p + b.p
  • Good conductors of electricity because the delocalised electrons in the metal carry electrical charge through the metal
  • Metals are good conductors of thermal energy because energy is transferred by the delocalised electrons
  • Atoms form layers - means they can slide over one another so therefore they are malleable (can be bent + shaped without breaking)
38
Q

Why are alloys made?

A

Metals are often too soft when pure, so they’re mixed with other metals to make them harder.

39
Q

How are alloys made? (3)

A
  • Different elements have different sized atoms.
  • So when another element is mixed with a pure metal, the new element will distort the layers of metal atoms.
  • This makes it more difficult for layers to slide over each other therefore the alloys are harder.
40
Q

What do the states of matter depend on?

A

How strong the forces of attraction are between the particles of the material.

41
Q

What is the strength of forces between particles determined by? (3)

A
  • The material (structure + types of bonding)
  • The temperature
  • The pressure
42
Q

What does the particles theory do?

A

Explains how the particles in each of the three states of matter are arranged.

43
Q

What does particle theory say about solids? (2)

A
  • Strong forces of attraction between particles
  • Particles are close together in fixed positions
44
Q

What does particle theory say about liquids? (2)

A
  • Weak forces of attraction between particles
  • Particles are randomly arranged and free to move around
45
Q

What does particle theory say about gases? (2)

A
  • Very weak forces of attraction between particles
  • Particles are free to move and do so constantly with random motion
46
Q

What are the drawbacks of the particle theory? (4)

A
  • Great model for explaining solids, liquids and gases but it isn’t perfect
  • Particles aren’t solid, inelastic or spheres - they’re atoms, ions or molecules
  • Doesn’t show forces between atoms, so we can’t know how strong they are
  • Not to scale
47
Q

What are bulk properties?

A

Properties such as density and m.p, which stays the same regardless of how many atoms or molecules you have in a sample.

48
Q

What do bulk properties depend on?

A

How the particles interact with each other, so a single atom/molecule wouldn’t behave in the same way.

49
Q

How does a solid change state to;
- a liquid
- a gas?

A
  • melting
  • sublimation
50
Q

How does a liquid change state to;
- a solid
- a gas?

A
  • freezing
  • evaporation
51
Q

How does a gas change state to;
- a liquid
- a solid?

A
  • condensation
  • desublimation
52
Q

What are the state symbols? (4)

A
  • (s) - solid
  • (l) - liquid
  • (g) - gas
  • (aq) - aqueous (dissolves in water)
53
Q

What are the diameters of coarse particles?

A

2,500 nm - 10,000 nm

54
Q

What are the diameters of fine particles?

A

100nm - 2500 nm

55
Q

What are the diameters of nanoparticles?

A

1nm - 100nm

56
Q

What is the surface area of nano particles like?

A
  • Have a very high SA:VOL
  • As particles decrease in size, SA:VOL increases - assuming they stay a similar shape
57
Q

What are 6 uses of nanoparticles?

A
  • As catalysts for fuel cells
  • In nanomedicine
  • In electronics
  • In deodorants
  • In suncream
  • In cosmetics
58
Q

How are nanoparticles used as catalysts for fuel cells?

A

Usually platinum because they have a high SA:VOL and only a tiny quantity are needed.

59
Q

How are nanoparticles used in nanomedicine?

A

Tiny particles are absorbed more easily by the body than most particles therefore deliver drugs to exactly where needed.

60
Q

How are nanoparticles used in electronics?

A

Some conduct electricity, so they can be used in electronics.

61
Q

How are nanoparticles used in deodorants?

A

Silver nanoparticles are added to some deodorant as they have anti bacterial properties.

62
Q

How are nanoparticles used in suncream?

A

Better than traditional materials at protecting skin from harmful Uv rays and better skin coverage.

63
Q

How are nanoparticles used in cosmetics?

A

Can be used to improve things like moisturisers without making them oily. They can deliver active ingredients to lower layers of the skin in anti-aging creams.

64
Q

What are the disadvantages of nanoparticles? (2)

A
  • Worried that they are available in lots of products before the effects on human health are fully understood, and we don’t know what the long-term impacts on health will be
  • Concerns that they may cause environmental damage

GCSE Chemistry (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions