Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

A Level Edexcel Chemistry > Topic 2-Bonding > Flashcards

Topic 2-Bonding Flashcards

1
Q

What is metallic bonding and describe features of metals?

A

Electrostatic attraction between positive ions and a sea of delocalised electrons.
Metals are malleable and ductile

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

What does the strength of metallic bonding depend on and the effect on melting and boiling point?

A

Metallic bonds depend upon the amount of protons
The more protons the stronger the metallic bond as greater nuclear charge pulls in valence electrons
This increases boiling and melting point as more energy required to overcome metallic bonds

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

What is Ionic bonding and explain some properties?

A

Bond between positive and negative ions held together by electrostatic forces of attraction
Involves transfer of electrons

High Melting point
Soluble in water as they are charged
Does not conduct electricity in solids
Cannot be shaped
Brittle-As repulsion between same charged ions are strong

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

What is covalent bonding?

A

Electrostatic attraction between positive nucleus and negative electrons
It forms between 2 non metals
Involves sharing of electrons

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

What evidence is there for the existence of ions?

A

Migration of ions on wet filter paper-electrolysis of copper chromate
Electron Density Maps

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

Why does Ionic bonding have high melting and boiling points?

A

Strong electrostatic forces of attraction between oppositely charged ions so more energy is required to break forces

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

Why can Ionic compounds conduct electricity in solution but not in solids?

A

In solutions,ions are free to move and carry charge so it can conduct electricity
In solids,ions cannot move

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

Explain the properties of Diamonds?

A

High Melting Point- as it has strong covalent binds so lots of energy is required to overcome these bonds

High strength as each carbon is joined to 4 others so has a coordination no. of 4,strong delocalised electrons

Cannot conduct electricity

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

Explain the bonding,structure and properties of graphite?

A

High Melting Point-Has lots of strong covalent bonds so lots of energy required to break bonds
Each Carbon bonded to 3 others

Strength- Low strength as it has weak intermolecular forces of attraction so layers can slide over each other

Can conduct electricity as it has delocalised electrons

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

How does Ionic charges and Ionic Radii affect Ionic bonding?

A

The Greater the charge of the ion,the stronger the Ionic bond and so a higher melting and boiling point

The smaller the Ionic radii the greater the Ionic bonding as electrostatic attraction is greater when Ionic radii is small so it is stronger and has a higher melting and boiling point

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

Explain how Ionic radius changes down the group?

A

Ionic Radius increases down the group as atomic number is greater so there is more electron shell

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

What is a dative covalent bond?

A

This is where one atom donates both electrons to a bond for example carbon monoxide
Contributes to donate both electrons to form a covalent bond

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

Explain the properties of giant covalent bonds?

A

Strong covalent bonds and strong electrostatic forces of attraction allow:
Very High Melting points
Extremely hard-strong bonds in the regular lattice,so atoms cannot slide past each other
Good thermal conductors
Insoluble-As atoms are more attracted to neighbours than to solvent molecules
Cannot conduct electricity

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

Explain the angle size difference between lone pairs and electron pairs?
Explain the effect of electron repulsion on angle size?

A

As you know,pairs of electrons will always repel so stronger repulsion means greater angle difference
Lone pairs have stronger repulsion so they have greater angle size

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

What is the Octet rule and what elements are exemptions and why?

A

Tendency of electrons to have 8 electrons in the outer shell
Elements in the 3rd row or below don’t need to follow the Octet rule as they can have more electrons as they can promote some electrons in a 3d subshell
They can have upto 18

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

What are hypervalent compounds?

A

Compounds that do not follow the Octet rule and can have more than 8 electrons in a subshell

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

What is a sigma bond?

A

Is the overlap of a covalent bond which passes the internucleaur axis
Single bonds are sigma

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

What is a pi bond?

A

Pi bonds are a bond between 2 covalent bonds where it passes the internucleur axis
Double bonds have 1 sigma and 1 pi bond
Triple bonds have 1 sigma and 2 pi bonds

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

What is a molecule?

A

An uncharged group of 2 or more atoms stuck together

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

What is a double bond?

A

Its where 2 pairs of electrons are shared between 2 elements

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

Explain how the length of a covalent bond is dependant on the relative atomic mass?

A

Greater relative atomic mass means that there is more electrons and greater nuclei distance so that means the length of the covalent bond is greater.

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

Explain how the proton number affects the length of a covalent bond?

A

The Greater the proton number,the greater the attraction between positive nuclei and outer electrons so this means atomic radius is smaller so length of covalent bond is smaller

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

How are dative bonds represented?

A

They are represented by 2 dots or 2 crosses or as an arrow

24
Q

What is needed for a dative bond to form?

A

An element/atom needs a lone pair of electrons to form a full outer shell
It requires an acceptor and a donor

25
What is the Valence Shell Electron pair repulsion theory and its purpose?
This is a theory used to predict the geometry of molecules based on minimising electron repulsion
26
How is the shape of a molecule determined?
It is determined by the electron pairs surrounding the central atom This is based on the fact that pairs of electrons repel other pairs of electrons This means electron pairs move as far as possible creating bigger bond angles
27
What angle does lone pairs decrease bond angle by and why?
Each lone pair decreases bond angle by 2.5 degrees and this is because they create repulsion A lone pair also counts as a region
28
What is the bond angle for tetrahedron?
It's 109.5
29
Describe the geometry of water,shape and bond angles
Water is a tetrahedron with a bent shape as it has 4 electron density regions(2 bonding pairs and 2 lone pairs) It has a bond angle of 104.5 and 109.5-2.5-2.5 is 104.5
30
Explain variations in melting temperature across period 3 in terms of structure and bonding?
Na,Mg,Al have metallic bonding,number of protons increase,radius decreases so metallic bond strength increases Si is a giant covalent molecule so lots of energy required to break covalent bonds Phosphorus is a simple molecular so it has low melting pointe as it has weak intermolecular forces
31
What is electronegativity?
The power/ability of an element to attract the shared pair of electrons in a covalent bond
32
Explain how electronegativity changes down a group?
Electronegativity decreases down the group as shielding increases which decreases the effective nucleur charge so the element is less likely to attract electrons as positive nuclear charge is lowered by shielding
33
Explain how electronegativity changes across a period?
Across a period,electronegativity increases as proton no increases so effective nucleur charge increases as atomic radius gets smaller
34
What is the Pauling Electronegativity of non polar,polar and Ionic compounds?
Non polar-0 to 0.5 Polar-0.5 to 1.7 Ionic-Greater than 2 and smaller than 4(4 is max and fluorine has EN of 4 )
35
What does electronegativity show in a compound?
In a compound such as HCL the element with a greater EN will have a greater share of the shared electron pair so its slightly more negative whereas the other is positive Cl has a greater EN so its delta negative
36
Explain how lone pairs affect electronegativity?
Molecules with one or more lone pairs on the central atom are always polar as it breaks the symmetry
37
What are intermolecular forces and the 3 examples?
Intermolecular forces are forces between molecules and are weaker than Ionic and covalent London forces(instantaneous dipole dipole bonds) Permanent dipole dipole forces Hydrogen bonding(strongest type)
38
What are London forces?
They are fluctuations in electrical distribution within atoms and molecules They can induce another temporary dipoles forming weak london forces They are instantaneous dipole forces
39
Explain how to increase strength of london forces?
Larger molecules(such as down the group) has larger electron clouds so stronger london forces Increase SA increases strength of london forces Greater electrons increase the strength
40
What are permanent dipole dipole forces and what compounds have these?
Polar compounds have permanent dipole dipole forces as they have some sort of electronegativity
41
Explain the strength of forces/bonding of london,hydrogen,dipole,covalent
London-weakest Dipole dipole Hydrogen-very strong Covalent-strongest
42
What is hydrogen bonding and what elements can it occur with?
Hydrogen bonding is the electrostatic attraction between negative oxygen and positive hydrogen They only occur in OH,FH,NH bonds
43
Why can hydrogen bonding only occur with elements:fluorine,oxygen and nitrogen?
These are the most electronegative elements so they draw the binding electrons away Lone pairs make the bond polarised
44
Factors affecting bond length and explain them?
Atomic radius-greater atom means more electrons shells so more shielding which reduces attraction resulting in longer bond length Greater attraction means shorter bind length
45
Explain why fluorine is more electronegative than bromine?
Less shielding,can form hydrogen bonds so more polar
46
Explain the relationship with solubility and bonding?
For a substance to dissolve in another: Bonds in the substance has to break Bonds in the solvent have to break New Bonds have to form between substance and solvent
47
Define electron affinity?
The first electron affinity (EA1) is the enthalpy change when 1 mole of electrons is added to 1 mole of gaseous atoms, to form 1 mole of gaseous ions each with a single negative charge under standard conditions
48
First electrons affinity is exothermic,explain why 2nd and 3rd are endothermic?
The second and third electron affinities are endothermic, as energy is absorbed This is because the incoming electron is added to an already negative ion Energy is required to overcome the repulsive forces between the incoming electron and negative ion Since these are endothermic processes, the values will be positive
49
Explain what characteristics lead to a shorter bond?
The Greater the electron density between atoms the stronger the attractive force,so atoms are pulled in further towards each other leading to a shorter bond
50
If a shape has 3 bonding parts and no lone pairs what is the name and bond angle of shape
Trigonal planar
51
If a shape has 4 bonding angles and no lone pairs what is the shape and angle
Tetrahedral 109.5
52
If a shape has 3 bond pairs and 1 lone pair what is the shape and angle
Trigonal pyramidal 107
53
Shape with 2 bond angles and 2 lone pairs shape and bond angle is
Bent 104.5
54
Shape with 5 bond pairs and no lone pair shape and bond angle
Trigonal bipyramidal 120 and 90
55
Shape with only 6 bond pairs shape and name
Octahedral 90 degrees

A Level Edexcel Chemistry (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions