Brainscape's Knowledge GenomeTM

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


See full index

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

Topic 2- Bonding, Structure and Properties of Matter Flashcards

1
Q

What is an ion?

A

Ions are charged particles- they acn be single atoms or groups of atoms.

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

How are ions formed?

A

Atoms lose electrons to form ions. They try to get a full outer shell like a noble gas. Atoms with full outer shells are very stable.

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

What happens when a metal forms an ion?

A

They lose electrons from their outer shell to form positive ions.

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

What happens when a non-metal forms an ion?

A

They gain electrons in their outer shell to form negative ions.

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

What relationship does the number of electrons lost or gained have to an ion?

A

It is the same as the charge on the ion, e.g. if 2 electrons are lost,the charge will be 2+.

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

From which groups are the elements most likely to form ions?

A

1 & 2, 6 & 7

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

What ions do group 1 and 2 form?

A

They lose electrons to form positive ions (cations)

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

What ions do group 6 & 7 form?

A

They gain electeons into their outer shell to form negative ions.

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

What groups form which ions?

A

• Group 1: 1+ ions
• Group 2: 2+ ions
• Group 3: 3+ ions
• Group 4: 4+ ions
• Group 5: 3- ions
• Group 6: 2- ions
• Group 7: 1- ions

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

What is ionic bonding?

A

• Happens when a metal and non-metal react together
• Metal atom loses electrons to form a positively charged ion
• Non-metal ion gains these electrons to form a negatively charged ion.
• These oppositely charged ions are strongly attracted to one another by electrostatic forces.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the structure of an ionic compound?

A

• Giant ionic lattice.
• Ions form a closely packed regular lattice arrangement.
• There are very strong electrostatic forces of attraction between oppositely charged ions, in all directions in the lattice.

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

What are the properties of ionic compounds?

A

• High melting point and boiling point: many strong bonds between the ions, needs a lot of energy to overcome this attraction.
• Ions are free to move when melted: when solid, the ions are held in place, so the compounds can’t conduct electricity. When ionic compounds melt, the ions are free to move and they can carry electric charge.
• Some ionic compounds dissolve in water: the ions seperate and are all free to move in the solution, so they’ll carry an electric charge.

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

What is a covalent bond?

A

A bond made by non-metals sharing pairs of electrons.

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

Why are covalent bonds strong?

A

The positively charged nuclei of the bonded atoms are attracted to the shared pair of electrons by electrostatic forces, making covalent bonds very strong.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do atoms share electrons in covalent bonds?

A

• Atoms only share electrons in their outer shells.
• Each single covalent bond provides one extra electron for each atom.
• Each atom involved generally makes enough covalent bonds to fill up its outer shell. Having a full outer shell gives them the electronic structure of a noble gas, which is very stable.

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

Advantages and disadvantages of dot and cross diagrams

A

• Useful for showing how ionic compounds are formed.
• Don’t show the structure of the compound.
• Don’t show size of the ions.
• Don’t show how they are arranged.

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

Advantages and disadvantages of displayed formula

A

• Great for showing how atoms are connected in large molecules.
• Don’t show the 3D structure of the molecule.
• Don’t show which atoms the electrons in a covalent bond have come from.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Advantages and disadvantages of 3D model

A

• Shows covalent bonds and their arrangement in space next to each other.
• 3D models can get confusing for large molecules where there are lots of atoms to include
• Don’t show where the electrons in the bonds have come from.

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

What is a simple molecular structure?

A

Simple molecular substances are made up of molecules containing a few taoms joined together by covalent bonds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

NEED TO KNOW SIMPLE MOLECULAR SUBSTANCES

A

• Hydrogen, H2
• Oxygen, O2
• Methane, CH4
• Chlorine, Cl
• Nitrogen, N2
• Water, H2O
• Hydrogen Chloride, HCl

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

What are the properties of simple molecular substances?

A

• Atoms within the molecules are held by strong covalent bonds
• The forces of attraction between the molecules are very weak
• Low melting/boiling point: only intermolecular forces need to be broken and not the covalent bonds.
• Most molecular substances are gases or liquids at room temperature.
• As the molecules get bigger, the strength of the intermolecular forces increase, so more energy is needed to break them, and the melting and boiling points increase.
• Molecular compounds don’t conduct electricity, simply because they aren’t charged, so there are no free electrons or ions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is a polymer?

A

Long chains of repeating units. They also have covalent bonds.

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

How are atoms linked in polymers?

A

Lots of small units are linked together to form a long molecule that has repeating sections. All the atoms are joined by strong covalent bonds.

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

What are the properties of polymers?

A

• The intermolecular forces between polymer molecules ade larger than between simple covalent molecules, so more energy is needed to break them. This means most polymers are solid at room temperature.
• The intermolecular forces are still weaker than ionic or covalent bonds, so they generally have lower boiling points or giant molecular compounds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the properties of giant covalent structures?

A

• All the atoms are bonded to each other by strong covalent bonds.
• They have very high melting and boiling points as lots of energy is needed to break the covalent bonds between the atoms.
• They don’t contain charged particles, so they don’t conduct electricity- not even when molten.

26
Q

What are the properties of diamond?

A

• Very hard: each carbon atom forms 4 covalent bonds in a very rigid giant covalent structure.
• High melting point: strong covalent bonds require lots of energy to break
• Doesn’t conduct electricity: has no free electrons or ions

27
Q

What are the properties of graphite?

A

• Each carbon atom forms three covalent bonds to create hexagonal layers.
• Ideal as a lubricating material: no covalent bonds between the layers so they’re free to move over each other.
• Can conduct electricity and thermal energy: each carbon atom also has one delocalised electron.
• High melting point: covalent bonds require lots of energy to break.

28
Q

What are the properties of graphene?

A

• Network of covalent bonds makes it very strong.
• Incredibly light: one atom thick.
• Can conduct electricity and thermal energy: has a delocalised electron.

29
Q

What is a fullerene?

A

Molecules of carbon, shaped like closed tubes or hollow balls.

30
Q

How are fullerenes arranged?

A

Mainly arranged in hexagons but can also contain pentagons and heptagons.

31
Q

What are the uses of fullerenes?

A

• Delivering drugs
• Industrial catalysts
• Lubricants

32
Q

Why can fullerenes be used to deliver drugs?

A

• They can be used to ‘cage’ other molecules.
• This fullerene structure forms around another atom or molecule.

33
Q

Why can fullerenes be used as industrial catalysts?

A

• Have a large surface area.
• Individual catalyst molecules could be attached to the fullerenes.

34
Q

Why can fullerenes be used as lubricants?

A

• Spherical structure
• Weak intermolecular forces which allow molecules of this fullerene to slide past each other.

35
Q

What are the properties of fullerenes?

A

• Can form nanotubes
• Ratio between the length and diameter is very high
• Nanotubes can conduct both electricity and thermal energy
• They also have a high tensile strength

36
Q

What are the uses of nanotubes?

A

Nanotubes can be used in electronics or to strengthen materials without adding much weight, e.g. tennis racket frames.

37
Q

What is metallic bonding?

A

The forces of attraction that hold the atoms together in a regular structure are known as metallic bonding. Metallic bonding is very strong

38
Q

Why is metallic bonding so strong?

A

• The electrons in the outer shell of the metal atoms are delocalised.
• There are strong forces of electrostatic attraction between the positive metal ions and the shared negative electrons.

39
Q

What substances are held together by metallic bonding?

A

Metallic elements and alloys.

40
Q

What produces all the properties of metals?

A

The delocalised electrons

41
Q

Why are metals solid at room temperature?

A

• Electrostatic forces between the metal atoms and the delocalised sea of electeons are very strong, so lots of energy needed to be broken.
• This means that most compounds with metallic bonds have high melting points and boiling points.

42
Q

Why are metals good conductors of electricity and heat?

A

The delocalised electron can carry electric charge and thermal energy through the wholenstructure

43
Q

Why are most metals malleable?

A

The layers of atoms in a metal can slide over each other, making metals malleable.

44
Q

Why are alloys harder than pure metals?

A

• Different elements have different sized atoms
• When another element is mixed with a pure metal, the new metal atoms will distort the layers of metal atoms, making it more difficult for them to slide over each other. This makes alloys harder than pure metals.

45
Q

How do the particles behave in a solid?

A

• Strong forces of attraction between the particles, which holds them close together in fixed positions to form a very regular lattice arrangement.
• The particles don’t move from fixed positions, so all solids keep a definite shape and volume, and don’t flow like liquids.
• The particles vibrate about their positions- the hotter the solid becomes, the more they vibrate (causing solids to expand slightly when heated).

46
Q

How do the particles behave in a liquid?

A

• In liquids, there’s a weak force of attraction between the particles. They’re arranged and free to move past each other, but they tend to stick closely.
• Liquids will have a definite volume but don’t keep a definite shape, and will flow to fill the bottom of a container.
• The particles are constantly moving with random motion. The hotter the liquid gets, the faster they move. This causes the liquids to expand slightly when heated.

47
Q

How do the particles behave in gases?

A

• In gases, the force of attraction between the particles is very weak- they’re free to move and are far apart. The particles in gases travel in straight lines.
• Gases don’t keep a definite shape or volume and will always fill any container.
• The particles move constantly with random motion. The hotter the gas gets, the faster they move. Gases either expand when heated, or their pressure increases.

48
Q

Particle theory advantages and disadvantages

A

• Great for explaining the three states of matter
• In reality, the particles aren’t solid or inelastic and they aren’t spheres| they’re atoms, ions or molecules.
• The model doesn’t show the forces between the particles, so there’s no way of knowing how strong they are.

49
Q

What are the state symbols?

A

• Solid (s)
• Liquid (l)
• Gas (g)
• Aqueous (aq)

50
Q

Describe the change from solid to liquid

A

• When a solid is heated, its particles gain more energy.
• This makes the particles vibrate more, which weakens the forces that hold the solid together.
• At a certain temperature, called the melting point the particles have enough energy to break free from their positions. This is called melting and the solid turns into a liquid..

51
Q

Describe the change from liquid to gas

A

• When a liquid is heated, again the particles get even more energy
• This energy makes the oarticles move faster, which weakens and breaks the bonds holding the liquid together.
• At a certain temperature, called the boiling point, the particles have enough energy to break their bonds. This is boiling. The liquid becomes a gas.

52
Q

Describe the change from gas to liquid

A

• As a gas cools, the particles no longer have enough energy to overcome the forces of attraction between them.
• Bonds form between the particles.
• At the boiling point, so many bonds have formed between the gas particles that the gas becomes a liquid. This is called condensing.

53
Q

Describe the change from liquid to solid

A

• When a liquid cools, the particles have less energy, so move around less.
• There’s not enough energy to overcome the attraction between the particles, so more bonds form between them.
• At the melting point, so many bonds have formed between the particles that they’re held in place. The liquid becomes a solid. This is freezing.

54
Q

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

A

• Depends on how strong the forces between the particles are
• The stronger the forces, the more energy is needed to break them, and so the higher the melting and boiling points of the substance.

55
Q

What is a coarse particle?

A

• Coarse particles have a diameter between 2500 nm (2.5 x 10^-6 m) and 10,000 nm (1 x 10^-5 m).
• They’re also called dust.

56
Q

What is a fine particle?

A

• Have a diameter between 100 nm (1 x 10^-7 m) and 2500 nm (2.5 x 10-6 m).

57
Q

What is a nanoparticle?

A

• Have a diameter between 1nm (1 x 10^-9 m) and 100 nm (1 x 10^-7 m).
• These are particles that contain only a few hundred atoms.
• Have high surface area to volume ratio.

58
Q

What are the uses of nanoparticles?

A

• They have a huge surface area to volume ratio, so they could help make new catalysts.
• They could deluver drugs right imto the cells where they’re needed
• Some nanoparticles conduct electricity, so they can be used in tiny electric circuits for computer chips.
• Silver nanoparticles have antibacterial properties. They can be added to polymer fibres that are then uses to make surgical masks and wound dressings and they can also be added to deodarants.
• Can be used in cosmetics. Used to improve moisturisers without making them really oily.

59
Q

What are the risks of using nanoparticles?

A

• The way they affect the body isn’t fully understood yet. May cause long term impacts on peoples health.
• Possible that when they are washed away they might damage the environment.

60
Q

NEED TO KNOW IONS

A

• Zinc: Zn 2+
• Iron: Fe 2+
• Lead: Pb 2+
• Copper (I): Cu +
• Copper (II): Cu2 +
• Silver: Ag +
• Bromide: Br 1-
•. Chloride: Cl 1-
• Oxide: O 2-
• Carbonate: CO3 2-
• Ammonium: NH 4+
• Hydroxide: OH -
• Sulfate: SO4 2-

AQA Chemistry (10 decks)

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