Brainscape's Knowledge GenomeTM

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


See full index

GCSE Chemistry > C3 - Structure and Bonding > Flashcards

C3 - Structure and Bonding Flashcards

1
Q

What is Ionic Bonding?

A

The transfer of electrons between a metal and a non-metal.

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

What is an Ionic Bond?

A

The strong bond of oppositely charged ions that are held together by strong electrostatic forces of attraction.

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

What holds ions together?

A

Strong electrostatic forces of attraction between oppositely charged ions.

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

What ions do metals form in an Ionic Compound?

A

Positive Ions - lose electrons

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

What ions do non-metals form in an Ionic Compound?

A

Negative Ions - gain electrons

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

How are the ionic bonds arranged?

A

In giant structures/lattices

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

What are the charges on the ions for each group?

A

Group:

1) 1+
2) 2+
3) 3+
4) 4+ or 4-
5) 3-
6) 2-
7) 1-
0) never as they’re electronically stable

Rule:

  • Group 1 atoms have 1 electron in their outermost shell.
  • Group 2 atoms have 2 electrons in their outermost shell.
    etc. ……
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the ‘Dot and Cross’ Method and how does it help with understanding Ionic Bonding?

A

The ‘Dot and Cross’ Method helps understand what occurs when atoms from 2 elements form an Ionic Bond. It makes it easier to visualise the transfer of electrons.

(See GoodNotes 3.3)

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

What happens when Mg (2.8.2) forms an Ionic Bond with O (2.6)?

A

Mg (2.8.2) reacts with O (2.6) to form MgO.

Mg needs to lose 2 electrons. O needs to gain 2 electrons also. To become an electronically stable compound, Mg transfers 2 electrons to the outershell of O. Magnesium Oxide (MgO) is formed (2.8).

Within the ionic compound:

  • Mg (2.8.2) beomces [Mg]2+ (2.8)
  • O (2.6) becomes [O]2- (2.8).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens when Al forms an Ionic bond with F?

A

Al (2.8.3) reacts with F (2.7) to form AlF3.

Aluminium needs to lose 3 electrons. But, Fluorine only needs to gain 1. So, you need 3 times as many fluorine atoms to each receive 1 electron to become stable.

Within the ionic compound:

  • Al (2.8.3) becomes [Al]3+ (2.8)
  • F (2.7) beomes [F]1- (2.8) - there are three [F]1- ions in the compound.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the chemical properties of a Giant Ionic Structure?

A
  • High Melting Point - strong ionic bonds operating in all directions.
  • Solid at room temperature
  • Great conductor of electricity and heat - when in a molten or dissolved state!!!
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When do ionic compounds conduct electricity?

A

Once in a molten or dissolved state:

  • the ions are free to move around and are attracted to oppositely charged ions.
  • they can carry the charge through the liquid.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why can ionic compounds only conduct electricity when in a molten or dissolved state?

A

The ions must be mobile (free to move around).

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

Why do ionic compounds NOT conduct electricity when in a solid state?

A

The ions are rigidly fixed in place - they are immobile and cannot carry a charge.

Most ionic compounds are solid at room temperature and therefore have to be melted or dissolved in water.

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

What electrode are metal and non-metal ions attracted to?

A

Metal ions - positively charged —> NEGATIVE ELECTRODE

Non-metal ions - negatively charged —> POSITIVE ELECTRODE

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

Why can seawater conduct electricity better than fresh water?

A

Because sea water has lots of ions (sodium ions and chloride ions). Therefore, an electrical charge is carried through seawater more easily than in freshwater.

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

What is Covalent Bonding?

A

The sharing of PAIRS of electrons in NON-METALS to form molecules.

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

What is a Covalent Bond?

A

The strong bond of atoms held together by shared pairs of electrons.

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

What are Intramolecular bonds?

A

The bonds within a molecule (between atoms).

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

What are Intermolecular bonds?

A

Bonds between the molecules of a substance.

This impacts melting point and boiling point.

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

Which 2 ways can you represent covalent bonding visually?

A

1) Venn Diagram with Dot and Cross
2) Number or covalent bonds e.g:

H—O—H

-Make sure it’s === for double, and — for single

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

How do 2 Hydrogen atoms form a covalent bond?

A

Both hydrogen atoms have 1 electron in their outermost shells as they are of the same element. Therefore they need to lose 1 electron to become stable. This means 1 pair of shared electrons is needed which forms a single covalent bond.

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

How do 2 Oxygen atoms form a covalent bond?

A

They both need to lose 2 electrons as oxygen is in group 6. Therefore 2 shared pairs of electrons are needed which means that a DOUBLE covalent bond is formed.

It’s a double as there are 2 shared pairs in 1 intersect in imaginary venn diagram.

24
Q

How does a Hydrogen atom form a covalent bond with a Chlorine atom?

A

Hydrogen needs to lose 1 electron and chlorine needs to gain 1 so 1 shared pair is needed to form a single covalent bond.

If you had to show this in a ‘Dot and Cross’, work out how many shared pairs there are and then fill in the rest of the electrons that are missing.

25
Q

How do 2 hydrogen atoms form a covalent bond with an oxygen atom? (Water)

A

There are 2 hydrogen atoms which means that they each want to lose 1 electrons. That’s 2 electrons that need to be lost in total. Oxygen wants to gain 2 electrons. Therefore 2 shared pairs of electrons are needed and water has 2 SINGLE covalent bonds. NOT A DOUBLE.

They are single because there are 2 intersects in the imaginary venn diagram.

26
Q

What are the 2 types of Covalently-bonded substances?

A

1) Simple covalent structures - made up of MOLECULES. (E.g H2O, CO2 etc…)
2) Giant covalent structures - made up of complex three-dimensional structures of ATOMS. (E.g Diamond, Graphite, Silicon Dioxide)

27
Q

What are the intramolecular and intermolecular forces like for simple covalent structures? What does this mean?

A

-Consist of molecules in which the atoms are joined by strong covalent bonds - STRONG INTRAMOLECULAR BONDS.

WEAK INTERMOLECULAR FORCES between the molecules - low melting points and low boiling points.

28
Q

In a simple covalent structure, the Intermolecular forces are ______.

A

Weak - covalent substances with simple structures are easier to break down (lower melting and boiling points).

29
Q

In a simple molecule, the Intramolecular forces are ______ because…..

A

Strong because of the strong covalent bonds that make up each atom.

30
Q

Can simple covalent structure conduct electricity?

A

No. The neutral molecules cannot conduct electricity at all.

31
Q

What are giant covalent structures? How are they arranged?

A

Complex three-dimensional network of atoms held together by strong covalent bonds.

Arranged in giant, regularly-structured lattices which are extremely strong due to the many bonds involved.

32
Q

What are 3 substances that are made up of giant covalent structures?

A

1) Diamond
2) Graphite
3) Silicon Dioxide

33
Q

What special properties do substances made up of giant covalent structures have?

A
  • Very high melting points and boiling points.
  • Insoluble in water
  • Extremely Hard
  • DO NOT conduct electricity (except graphite!!!)
34
Q

What is the hardest natural substance known to man? What is its boiling point?

A

Diamond

BP = 4827°C

35
Q

Why is diamond so hard?

A

Each carbon atom forms 4 strong covalent bonds, arranged in a perfectly symettrical lattice.

In order to break a diamond, immense pressure is needed.

36
Q

How are the atoms in graphite (form of carbon) arranged?

A
  • The carbon atoms are arranged in hexagons which form different layers.
  • Between the layers, there are no covalent bonds, so the layers can EASILY SLIDE OVER EACH OTHER. (*Like cards sliding off the deck of a pack of playing cards.)
  • Each carbon atom forms three strong covalent bonds.
  • But carbon has 4 electrons in its outer shell - leaving one electron per atom spare.
37
Q

What are delocalised electrons?

A

Delocalised electrons are electrons that can move freely around in a substance.

38
Q

What role do delocalised electrons play in graphite?

A

Delocalised electrons enable graphite to be able to conduct electricity as each mobile outer electron can move freely along the layers of carbon atoms.

39
Q

What are the properties of graphite?

A

1) Excellent electrical and *thermal conductor -
* each delocalised electron gains energy and moves faster - rapidly transferring thermal energy along the layers of graphite.
2) Smooth, slippery and soft.

40
Q

Why can diamond not conduct electricity?

A

Because diamond has no delocalised electrons.

Graphite is the ONLY Giant Covalent Structure that can conduct electricity.

41
Q

What is graphite used as?

A

As pencil lead and a lubricant.

42
Q

What are fullerenes? What shape are they?

A

Fullerenes are hollow, spherical, cage-like carbon molecules, usually made up of *hexagonal rings of carbon atoms. (E.g C50, C60, C70)

Shape = SPHERICAL

*Sometimes made up of pentagonal and heptagonal rings of carbon.

43
Q

When and by whom was it discovered that carbon atoms could behave like this?

A

1985 - Scientists scientists tried to re-create conditions that accounted for long chains of carbon atoms that existed in outer space.

By doing this, they created the C60 molecule by chance - it had 60 carbon atoms - named ‘Buckminsterfullerene.

Professor Sir Harry Kroto suggested that the carbon atoms were arranged in a cage-like structure, similar to the panels of a football.

44
Q

What are the properties of fullurenes? What role could fullerenes play in the world of medicine in the future?

A

Properties:

  • High Tensile Strength
  • High electrical and thermal conductivity (delocalised electrons)

Future (medical industry):
-Fullerenes could be used for drug-delivery into the body. For example, the cage-like structures could be used as ‘bucky mules’ to deliver radioactive atoms to fight cancer.

45
Q

What is graphene? How was it formed?

A

Graphene is an exciting new material that was made when scientists at Manchester University used a piece of tape to rip off a layer of graphite. They then looked at it under a powerful electronic microscope.

Summary:
-Graphene is a single layer of graphite and therefore is one atom thick.

46
Q

What are the properties of graphene?

A
  • Excellent electrical and thermal conductor (even better than graphite).
  • Low density
  • Very reactive - most reactive form of carbon.
47
Q

What could graphene’s first large-scale application be?

A

Graphene’s first large scale application is likely to be as flexible electronic displays - watching a film on your wrist or sleeve.

48
Q

How are the atoms in a metal arranged?

A

The atoms in metals are closely packed and are arranged in regular layers, one on top of another.

49
Q

How does metallic bonding work? What properties does this give metals?

A

Metals are arranged in giant lattices of positively charged ions.

  • When atoms are arranged like this in a metal, they all give up their outer electrons to share them in the lattice.
  • This makes all of the metal atoms in the lattice positive ions.
  • The outer electrons shared throughout the metals are called delocalised electrons. These electrons can move freely throughout the lattice, forming a ‘sea of delocalised electrons’.
  • The positively charged metal ions are held together by strong forces of attraction between them and the negative electrons.

Properties:

  • Very strong - regular structure
  • High melting and boiling points - regular structure
  • Good conductor of electricity and heat - delocalised electrons
50
Q

Why can pure metals be bent and shaped?

A

Pure metals are very malleable and can be bent and shaped.

This is because the regular layers of atoms in a pure metal are able to slide over each other easily.

51
Q

Why can the layers of pure metals slide over each other easily?

A

Because of the regular arrangement of layers within a giant metallic structure.

52
Q

What is an alloy?

A

An alloy is a mixture of 2 or more elements, at least one of which is a metal.

53
Q

Why are alloys harder than pure metals?

A

Because the atoms of different elements distort the regular arrangement of a metal - so the layers can no longer slide over eachother.

54
Q

Why can thermal and electrical energy be transferred through metals?

A

Because of the ‘sea’ of delocalised electrons that can carry thermal and electrical energy through the metallic structure.

55
Q

Why do metals have high melting points?

A

Because of the regular and structured layers held together by strong electrostatic forces of attraction.

GCSE Chemistry (17 decks)

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