C2.3

Question 1

How many bonds can carbon form?

Answer 1

Carbon can form 4 covalent bonds

Question 2

How do vast arrays of natural and synthetic organic compounds occur with carbon?

Answer 2

As carbon has the ability to form families of similar compounds, chains or rings

Question 3

Explain the properties of diamond in term of structure and bonding

Answer 3

Diamond is a giant covalent structure in which each carbon atom is covalently bonded to 4 other carbon atoms

Question 4

Explain the properties of graphite in term of structure and bonding

Answer 4

Graphite is a giant covalent structure where each carbon atom is covalently bonded to 3 other carbon atoms. This means 1 electron in each atom is delocalised

Question 5

Explain the properties of graphene in term of structure and fullerenes

Answer 5

Graphene is a carbon allotrope that resembles a single layer of graphite

Question 6

Explain the properties of fullerenes in term of structure and bonding

Answer 6

Fullerenes form a large family of carbon allotropes in which the molecules are shaped as tubes or balls

Question 7

What happens to the bonds when a solid melts?

Answer 7

Some bonds break when a solid melts

Question 8

What happens to the bonds when a liquid boils?

Answer 8

All remaining bonds break when a liquid boils

Question 9

What happens to the bonds when a gas condenses?

Answer 9

Some bonds form when a gas condenses

Question 10

What happens to the bonds when a liquid freezes?

Answer 10

All remaining bonds form when a liquid freezes

Question 11

What bonds are involved in state changes for a metal and what are the strength of these?

Answer 11

Metallic bonds - strong

Question 12

What bonds are involved in state changes for an ionic compound and what are the strength of these?

Answer 12

Ionic bonds - strong

Question 13

What bonds are involved in state changes for a giant covalent structure and what are the strength of these?

Answer 13

covalent bonds - strong

Question 14

What bonds are involved in state changes for a simple molecule and what are the strength of these?

Answer 14

intermolecular forces - weak

Question 15

Are metals malleable or brittle and why is this?

Answer 15

Metals are malleable as they are held in a lattice by forces that attract them to a ‘sea’ of delocalised electrons

Question 16

Are giant covalent structures malleable or brittle and why is this?

Answer 16

Giant covalent structures are brittle as their atoms are all held together by strong covalent bonds

Question 17

Are ionic compounds malleable or brittle and why is this?

Answer 17

Oppositely charged ions are held in place by strong ionic bonds, which means ionic compounds are brittle

Question 18

Are simple molecules and polymers malleable or brittle and why is this?

Answer 18

Simple molecules and polymers are attracted to each other by weak intermolecular forces which are easily broken, so they are brittle

Question 19

Can metals conduct electricity and why is this?

Answer 19

Metals conduct electricity because their delocalised electrons are free to move through the lattice

Question 20

Can simple molecules conduct electricity and why is this?

Answer 20

No, because they have no delocalised electrons

Question 21

What are nanoparticles and what is their size?

Answer 21

Nanoparticles are particles between 1nm and 100nm across which contain only a few hundred atoms

Question 22

Compare nano sizes to the size of an atom

Answer 22

A nanoparticle is around 10^-9 m, while an atom is 10^-10 m

Question 23

Describe the surface area:volume of nanoparticles and how this affects properties
What are the uses of nanoparticles?

Answer 23

Surface area:volume of a nanoparticle is very large, and this makes them useful for:
cosmetics
medicines
paints
catalysts to speed up industrial chemical reactions
self-cleaning windows, ovens & clothes

Question 24

How are the properties of nanoparticles related to their uses?

Answer 24

Nanoparticles are very small, so they are able to have many different uses

Question 25

Explain the possible risks associated with nanoparticles

Answer 25

Nanoparticles are so tiny they may be breathed in, absorbed by the skin or pass into cells. They may take a long time to break down once released into the environment, and toxic substances may stick to their surfaces