Allotropes of Carbon (pg 118)

Question 1

What are Allotropes?

Answer 1

they are different structural forms of the same element in the same physical state.

(carbon got lots)

see diagram on page 118

Question 2

What is Diamond made up of?

Answer 2

Diamond has a giant covalent structure, made up of carbon atoms, made up of four covalent bonds

Question 3

why is Diamond really hard?

Answer 3

its hard as it is made up of carbon atoms that each form four covalent bonds. This makes it very hard

The strong covalent bonds take a lot of energy to break and give diamond a very high melting point.

Question 4

Why doesn’t diamond conduct electricity?

Answer 4

because it has no free electrons or ions

Question 5

Graphite contains sheets of what shape?

Answer 5

Hexagons

see diagram on page 118

Question 6

In graphite each carbon atom only forms three covalent bonds, what do this create?

Answer 6

they create sheets of carbon atoms arranged in hexagons

Question 7

Are there any covalent bonds between the hexagon layers of Graphite?

Answer 7

No. they are held together weakly, or they’re free to move over each other.

This makes Graphite soft and slippery, so it’s ideal as a lubricating material.

Question 8

Has Graphite got a high melting point and why?

Answer 8

Yes has a high melting point - the covalent bonds in the layers need loads of energy to break.

Question 9

How many carbon’s four outer electrons are used in bonds, in graphite?

Answer 9

Three out of four outer electrons are used in bonds, so each carbon atom has one electron that’s delocalised (free) and can move. So graphie conducts electricity and thermal energy

Question 10

What is Graphene?

Answer 10

it is ONE layer of Graphite

It is a sheet of carbon atoms joined together in hexagons.

The sheet is just ONE atom thick, making it a two-dimentional substance

The network of covalent bonds makes it very strong. It also incredibly light, so can be added to composite materials to improve the strength without adding much weight.

(see diagram)

Question 11

Do Graphene contain delocalised (free) electrons, and what do this mean?

Answer 11

Yes it contains delocalised electrons, (like Graphite), so can conduct electricity through the whole structure.

This mean it has the potential to be used in electronics

Question 12

What are Fullerenes?

Answer 12

Fullerenes are molecules of carbon, shaped like closed tubes or hollow balls.

They’re mainly made up of carbon atoms arranged in hexagons, but can also contain pentagons (rings of five carbon atoms) or heptagons (rings of seven carbon atoms).

see diagrame on page 118

Question 13

What are Fullerenes used for?

Answer 13

they can be used to cage other molecules. The fullerene structure forms around another atom or molecule, which is then trapped inside.

This could be used to deliver a drug into the body

Question 14

Describe how Fullerenes could help make great industrial catalysts?

Answer 14

They have a huge surface area, so they could help make great industrial catalysts -

individual catalyst molecules could be attached to the fullerenes.

Fullerenes also make great lubricants.

Question 15

Fullerenes can form nanotubes, what are these?

Answer 15

nanotubes are tiny carbon cylinders.

the ratio between the length and the diameter of a nanotube is very high.

see diagram page 118

Question 16

Can Nanotubes conduct both electricity and thermal energy (heat)?

Answer 16

Yes

Question 17

Nanotubes have a high tensile strength, what do this mean?

Answer 17

they don’t break when they’re stretched.

Question 18

What is nanotechnology?

Answer 18

Technology that uses very small particles

Question 19

What can nanotubes be used in?

Answer 19

electronics or to stregthen materials without adding much weight, such as in tennis racket frames.

Question 20

Give some uses of fullerenes?

Answer 20

lubricants
catalysts
drug delivery
strengthen materials

Question 21

what is the properties of diamond?

Answer 21

It is the haardest known substance known natural substance.
It also chemically resistant, and has the highest thermal conductivity of any natural material.

These properties make it suitable for use as a cutting tool, and for other uses where durability is required.

Question 22

What is the properties of Graphite?

Answer 22

High melting point and boiling points
many covalent bonds are strong and substantial energy is needed to break them
good electrical conductivitsoftness. the weak forces between graphite layers allow them to slide.

Question 23

What is Graphite used for?

Answer 23

Pencils,
lubricants (greace or oil to keep engines working),
cruibles (a ceramic or metal container in which metals or other substances may be melted or sujected to very hig temperatures)
foundry facings (a carbonaceous material applied to the surface of a sand mold to prevent the molten metal from penetrating and reacting with the sand of the mold), polishes,
arc lamps,
batteries,
brushes for electric motors
and cores of nuclear reactors

Question 24

What is Graphine and what is it used for?

Answer 24

Graphene is a material with an unprecedented hardness, is ten times stronger and six times lighter than steel. It is produced from Graphite which we find in the cenre of pencils, expect that Graphene consists of a single layer of carbon atoms.

Transport medicine, electronics, energy, defence,

It has a lot of promise for additional application; anit corrosion coatings and paints, efficient and precise sensors, faster and efficent electronics, flexible dislays, solar pannels, faster DNA sequencing, drug delivery

Question 25

What properties do Fullerenes have?

Answer 25

The fullerene structure is unique in that the molecule is borderless, uncharged, has no bundaries, no dangling bonds, and o unpaired electrons.

these characteristics distinguish fullerene from other crystal structures, such as graphite or diamond, which have edges with dangling bonds and electrical charges.

Question 26

What is fullerene used for?

Answer 26

they are used in the medical field as light-activated antimicrobial agents. It is also used in several biomedical applicaitons including the design of high performance MRI contrast agents, X-ray imaging contrasts agents, photodynamic therpy and drug gene delivery.

Fullerene molecules are made of carbon atoms, and their shapes are as hollow sphere, ellipsoid or tube, spherical fullerenes are also referred to a bucky balls, they are carbon clusters, whose surface formed by 12 pentagons and any number of hexagons.

Question 27

What is a Buckminsterfullerne?

Answer 27

Buckminsterfullerene was the first fullerene to be discovered. It’s got the molecular formlar C60 and forms a hollow sphere.

see diagram on page 118