Carbon lattices and carbon nanomaterials

Question 1

Covalent network lattice

Answer 1

Continous 3D lattice of non metallic atoms joined by strong covalent bonds

Question 2

Diamond is a

Answer 2

covalent network lattice

Question 3

Diamond properties

Answer 3

Very hard
Sublimes at high temperatures
Does not conduct electricity
Conducts heat

Question 4

Diamond very hard

Answer 4

Strong covalent bonds continuous throughout lattice with atoms held in fixed positions

Question 5

Diamond sublimes at high temperatures

Answer 5

Large amount of energy needed to disrupt the lattice. At high temperatures, as solid changes to a gas, all bonds break, atoms are free to move independently

Question 6

Diamond does not conduct electricity

Answer 6

All electrons are localised and are not free to move and carry an electric current

Question 7

Diamond conducts heat

Answer 7

Atoms of carbon held together very tightly and heat is conducted by lattice vibrations which have a high velocity and frequency due to the strong bonding between the carbon atoms and high symmetry of the lattice

Question 8

Graphite is a

Answer 8

covalent layer lattice

continous 2D covalent layer lattice of carbon atoms

Question 9

Graphite structure

Answer 9

Each C atom is covalently bonded to 3 other C atoms within the same layer.
Forces between layers are weak dispersion forces

Question 10

Graphite properties

Answer 10

Moderately good electrical conductor
Soft and greasy
High sublimation point

Question 11

Graphite moderately good conductor of electricity

Answer 11

4th electron from each C atom is delocalised and free to move within the layer and conduct electricity

Question 12

Graphite soft and greasy

Answer 12

Forces between layers are weak and can be made to slide over each other easily

Question 13

Graphite high sublimation point

Answer 13

The covalent bonds within the layers are strong and therefore the temperature to disrupt the lattice is very high

Question 14

Amorphous forms of carbon

Answer 14

Contains irregularly packed tiny crystals of graphite and other non uniform arrangements and has no consistent structure
formed from the combustion of wood and other plant matter

Question 15

Allotropes

Answer 15

Different forms of the same element

atoms bonded in different specific ways and given significantly different properties

Question 16

Fullerenes

Answer 16

Atoms arranged in a series of hexagons and pentagons

Each C has 3 covalent bonds, leaving one delocalised electron and the possibility of electrical conductivity

Question 17

Graphene

Answer 17

Single layer of graphite

extremely strong

Question 18

Nanotubes

Answer 18

Long hollow structure with walls formed from graphene

extremely strong and excellent conductors of heat and electricity