C2 - Bonding, Structure, and Properties of Matter

Question 1

How do you show ionic bonding?

Answer 1

Dot and cross diagram

Question 2

Cons of dot and cross diagrams

Answer 2

• don’t show the structure of the compound
• don’t show the size of the ions

Question 3

What structure do ionic compounds have?

Answer 3

Giant, regular lattice

Question 4

What type of forces in giant ionic lattices?

Answer 4

Strong electrostatic forces of attraction between oppositely charged ions.

Question 5

What is the melting point of an ionic compound like?

Answer 5

High because the strong electrostatic forces of attraction between the ions take lots of energy to overcome.

Question 6

Conductivity in ionic compounds

Answer 6

Can’t conduct as a solid, when melted the ions are free to move and can carry an electric charge

Question 7

What are covalent bonds?

Answer 7

Sharing electrons

Question 8

Are covalent bonds weak or strong and why?

Answer 8

Strong because the positively charged nuclei of the bonded atoms are attracted to the shared pair of electrons.

Question 9

What are the three ways to show covalent bonds?

Answer 9

• dot and cross
• displayed formula
• 3D model (ball and stick)

Question 10

What is the structure of substances that contain covalent bonds?

Answer 10

Simple molecular structures.

Question 11

What are the forces like in simple molecular structures?

Answer 11

Molecules are held together with very strong covalent bonds.
The forces of attraction between the molecules are very weak - weak intermolecular forces.

Question 12

Why does the boiling point of simple molecular structures increase as the size of the molecules increase?

Answer 12

The strength of the intermolecular forces increases so more energy is needed to break them.

Question 13

Three facts about diamond

Answer 13

1 - each carbon forms 4 covalent bonds so it is very hard
2 - the strong covalent bonds take a lot of energy to break so diamond has a high melting point
3 - doesn’t conduct electricity because no free electrons

Question 14

Why is graphite soft and slippery?

Answer 14

There aren’t any covalent bonds between the layers - they are held together weakly

Question 15

What are fullerenes?

Answer 15

Molecules of carbon shaped like closed tubes or hollow balls.

Question 16

What is the molecular formula for buckminsterfullerene?

Answer 16

C60 (60 in subscript)

Question 17

Why could fullerenes be used to deliver drugs around the body?

Answer 17

They can be used to ‘cage’ other molecules.

Question 18

Why could fullerenes be used as catalysts?

Answer 18

They have a huge surface area.

Question 19

4 uses of fullerenes

Answer 19

1 - to deliver drugs around the body
2 - industrial catalysts
3 - electronics
4 - to strengthen materials without adding much weight e.g. tennis racket frames

Question 20

What are the forces in metallic bonding?

Answer 20

Strong forces of electrostatic attraction between the positive metal ion and the negative electron.

Question 21

True or false: Ionic, covalent, and metallic bonds all contain delocalised electrons

Answer 21

False
Ionic - yes
Covalent - no
Metallic - yes

Question 22

Why are metals malleable?

Answer 22

They are made up of layers that can slide over each other.

Question 23

Why are alloys harder than pure metals?

Answer 23

The different sized atoms distort the layers, making it difficult for them to slide over each other.

Question 24

Problems with the particle theory model

Answer 24

• particles aren’t solid
• particles aren’t spheres
• model doesn’t show the forces between particles

Question 25

Formula for surface are to volume ratio

Answer 25

surface area/volume

Question 26

What happens to the surface area to volume ratio as the particle size decreases?

Answer 26

Increases

Question 27

5 uses of nanoparticles

Answer 27

1 - catalysts (large surface area : volume)
2 - deliver drugs right into the cells that need them
3 - tiny electric circuits
4 - silver nanoparticles have antibacterial properties
5 - cosmetics