Allotropes

B Y A N N A R U B I N S T E I N A N D A M B E R T R E G O N I N G

8 U

What is an Allotrope?

Allotropes are the different forms of an element.

They will still belong to the same element, even though their physical properties are different.

Diamond , charcoal and Graphite are examples of this.

They are all allotropes of carbon, but their properties are very different.

Graphite

Diamond is made entirely of carbon, but is arranged in a “honeycombed” fashion.

Diamonds are one of earth’s hardest materials.

Graphite is most commonly found in pencils.

It is a very soft mineral but has a high melting point.

As graphite has a giant lattice structure, it is very hard to break apart.

High temperatures are needed to break these strong bonds to turn it into a liquid state.

The melting point of graphite is 3500c and 6332f , specific gravity is 2.25, pounds per cubic inch is.812.

Allotropes of Carbon

Diamond

•Diamond do not melt, it sublimes (solid-gas) at 3642 degrees Celsius. •Diamonds are usually used for jewellery but can also be used for cutting edges.

Each carbon atom is bonded to 4 other carbon atoms in a 3-dimensional covalent network. All valence electrons are used in bonding.

Each carbon atom is bonded to 3 other carbon atoms in layers with delocalised electrons between the layers.

Monoclinic Sulfur

Sulphur has many allotropes, in this sense it is second only to carbon.

Rhombic Sulfur is a bright yellow solid that is most stable at room temperature.

All forms of sulfur gradually turn into this if left standing.

Rhombic sulfur crystals are formed as fat, short diamond-like structures.

Rhombic crystals are formed at temperatures below 96 degrees Celsius

Sulphur has two accepted spelling, but mainly it is “Sulfur”

Monoclinic sulfur is formed as long, thin rectangular crystals.

Monoclinic Sulfur is formed above 96 degrees Celsius.

Allotropes of Sulphur

Rhombic Sulfur

Converting Allotropes?

"Allotropy or allotropism is a behavior exhibited by some chemical elements: these elements can exist in two or more different forms, known as allotropes of that element. In each allotrope, the element's atoms are bonded together in a different manner." Conversion, therefore (logically) would mean that one would be able to reduce the carbon allotrope to atoms and then re-assemble them into a different allotrope. For example, in order to form a diamond allotrope from a group of carbon atoms requires enormous amounts of pressure and temperature.

The third allotrope of Carbon.

In 1985 a third allotrope of Carbon was discovered by Sir Harry Kroto.

This was known as Buckminsterfullerene or Bukkeyeballs.

It represents the famous shape of a ball.

It has a geodesic structure made up of triangles.

An allotrope is one of two (or

more) forms of an element.

The two allotropes of Carbon

are diamond and graphite.

Graphite has a melting point of

3730°C and Diamond has a melting

point of 4500°C. They are high

because there are very strong

Carbon bonds in graphite and

diamond, so lots of energy is

required to break them.

Graphite can be found in pencils. It

is soft, so as you write, some

graphite breaks off and transfers

onto the paper.

As diamond is the strongest

substance known (due to the

strong carbon bonds formed in a

tetrahedron) it is used for

industrial cutting and polishing

tools.

Sulphur also has two allotropes.

They are monoclinic sulphur and

rhombic sulphur

A third allotrope of carbon was discovered in 1985 at the University of Sussex by Sir Harry Kroto. It was called Buckminsterfullerenes. It looks a bit like a football.

By Eve and Anjli

By Charlotte Woods & Millie Hague

The Structures of Allotropes

The structure of a diamond The structure of Graphite

You Should Know That:

DID YOU KNOW: Melting point and boiling points are determined by the strength of bonds

between atoms and molecules.

Using Allotropes

• Diamonds are useful for many reasons; Ranging from expensive jewellery to fatal weapons, because they have such a dense molecular structure, they do not break easily. They are the hardest substance known to man!

• Graphite is really useful for everyday chores.

• Pencils are made from graphite (lead)

• It is reasonably strong.

Sulphur

An Allotrope:

• Rhombic Sulphur

An Allotrope:

• Monoclinic Sulphur

Allotropes of Carbon. A form of allotropes are graphite and diamonds, chemical element would be carbon.

An allotrope is a substance consisting of one type of atom.

Carbon is the substance which is contained in most allotropes e.g. graphite and diamonds. Also

in other allotropes there are sulphur, oxygen and phosphorous.

SUBSTANCE TEXTURE USED FOR

Diamonds Hard Cutting other Diamonds

Graphite Soft Writing and Drawing

Examples of allotropes of carbon.

Allotropes of carbon, with giant covalent

structures have very high melting points

because alot of strong covalent bonds must be

broken.

e.g. graphite has a melting point of 3,600

Celsius.

The 2 main allotropes of Sulphur

are;

1. Rhombic sulphur

2. Monoclinic sulphur

Examples of allotropes of Sulphur.

One allotrope can be converted into

another allotrope by heat. When

one allotrope is heated it turns into

another type but when the allotrope

cools down it turns back to its

original state.

Allotropes

By Josie AND rOSY

What are allotropes?

• An allotrope is a variant of a substance on the molecular level. Consisting of only one atom

Name the two allotropes of carbon

• Diamond and graphite are the two allotropes of carbon

Find diagrams of their structure, how their atoms are arranged

Diamond Graphite

Have they got high and low melting points and

why • Yes diamonds and graphite's

both have high melting points because they have strong forces keeping them tight together.

Uses of diamonds

• Diamond is a fascinating mineral it is chemically resistant and it is the hardest known natural substance. Diamond has a high index of refraction, high dispersion and high lustre.

Uses of Graphite

• Graphite is used as a substance found in lead in pencils, also an electrical conductor and also a lubricant

allotropes of sulphur

• Rhombic Sulphur – a yellow crystalline solid which crystallises from a solution of carbon disulphide

• Monoclinic sulphur – A yellow crystalline solid which is obtained by allowing molten sulphur to solidify.

How can one allotrope be converted to the other

• Rhombic crystals are short and fat diamond like structures but monoclinic crystals are long and thin rectangular prisms, rhombic crystals are formed under 96°c (formed when heating sulphur crystals) in conclusion They can be converted with heat

Diamond is used in jewellery because it sparkles and reflects light in an attractive way. Its properties include: •Lustrous (shiny) •Colorless and transparent •Hard •High melting point •Doesn’t dissolve in water •Does not conduct electricity

Carbon Diamond Graphite

Allotropes are forms of an element that exist in the same state (solid, liquid or gas) but have different properties because their atoms are arranged differently

Like diamond, its properties include: •Lustrous •High melting point •Insoluble in water Also, unlike diamond, graphite is: •Black and opaque •Slippery •An electrical conductor Graphite is used inside pencils. It slips easily off the pencil onto the paper and leaves a black mark.

Carbon has different forms or 'allotropes', including diamond, graphite and fullerenes. Their properties make them useful for different purposes.

Scarlet and Lisa 8U

Sulphur has two most known allotropes: Rhombic Sulphur and Monoclinic Sulphur

Rhombic Sulphur Monoclinic Sulphur Sulphur

Water, Steam and ice are not allotropes because the arrangement of them are always the same: H²O

A fresh sample of sulfur is heated to just above the melting point, then allowed to cool and crystallize slowly as monoclinic sulfur.

Crystals of rhombic sulfur are formed by dissolving Sulphur in a warm solvent, then allowing the solution allowed to cool and evaporate.

Sulphur can be dissolved and melted to create it’s allotropes.

Scarlet and Lisa 8U

Allotropes are

different forms of

the same

element, where

atoms combine in

different ways.

The two allotropes

of carbon are

diamonds and

charcoal.

They both have high

melting points because

a large amount of

energy is required to

break the strong

carbon bonds in

graphite and diamond.

Graphite is used in pencils because

it is very soft. Therefore it comes off

on the paper and leaves a mark.

Diamond is used in weapons

because it is very hard and sharp so

it can cut through things.

Carbon

Sulphur

The two allotropes of

sulphur are Rhombic

Sulphur and

Monoclinic Sulphur

To convert one allotrope of

sulphur to another you heat it.

By Ashti and Megan 8U

here is a diagram of:

By Lucy , Alicia & Maia

Definition of allotropes: One of two or more existing forms of an element

The allotrpoes of carbon are:

Diamond. Diamond has the highest melting point – 3927 degrees Celsius.

Graphite. Graphite has a high melting point - 3652 – 3697 degrees Celsius

They have extremely high melting points because of their strong molecular structure. Melting point

is the temperature required to break the intermolecular bonds between molecules of a substance.

This means the bonds such as carbon bonds and polar attractions between the individual molecules

of a substance must be broken so the molecules can flow past each other in a liquid state.

Uses of Diamond

Diamond is chemically resistant and it is the hardest known natural substance. These properties

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

also has special optical properties such as a high index of refraction, high dispersion and high luster.

These properties help make diamond the world's most popular gemstone.

Uses of Graphite

They depend mainly upon its type - amorphous, lumpy or flake. The flake graphite is known

to show very low resistance to electrical conductivity. More the flaky particles, lesser the

resistance and bulk density. This particular characteristic of flake graphite makes it useful in

manufacturing of carbon electrodes, brushes and plates needed in dry cell batteries and the

electrical industry. These days, amorphous or crystalline graphite has replaced flaky graphite

in the production of brushes and plates.

Graphite crucibles are used for melting aluminum, brass and other non-ferrous metals.

By Lucy , Alicia & Maia

These crucibles are produced by mixing graphite, sand and clay together and pressing it on

the article at a high temperature. Flake and crystalline forms of graphite are the most used

in manufacturing of crucibles.

Monoclinic Sulphur

Rhombic Sulphur

- rhombic crystals are short and fat diamond like structures while monoclinic crystals are

long and thin rectangular prisms

- rhombic crystals are formed under 96°C

while monoclinic crystals are formed above 96°C (formed when heating sulphur crystals)

So therefore they can be converted using heat.

By Lucy , Alicia & Maia

Definition of allotropes: One of two or more existing forms of an element

The allotrpoes of carbon are:

Diamond. Diamond has the highest melting point – 3927 degrees Celsius.

Graphite. Graphite has a high melting point - 3652 – 3697 degrees Celsius

They have extremely high melting points because of their strong molecular structure. Melting point

is the temperature required to break the intermolecular bonds between molecules of a substance.

This means the bonds such as carbon bonds and polar attractions between the individual molecules

of a substance must be broken so the molecules can flow past each other in a liquid state.

Uses of Diamond

Diamond is chemically resistant and it is the hardest known natural substance. These properties

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

also has special optical properties such as a high index of refraction, high dispersion and high luster.

These properties help make diamond the world's most popular gemstone.

Uses of Graphite

They depend mainly upon its type - amorphous, lumpy or flake. The flake graphite is known

to show very low resistance to electrical conductivity. More the flaky particles, lesser the

resistance and bulk density. This particular characteristic of flake graphite makes it useful in

manufacturing of carbon electrodes, brushes and plates needed in dry cell batteries and the

electrical industry. These days, amorphous or crystalline graphite has replaced flaky graphite

in the production of brushes and plates.

Graphite crucibles are used for melting aluminum, brass and other non-ferrous metals.

By Lucy , Alicia & Maia

These crucibles are produced by mixing graphite, sand and clay together and pressing it on

the article at a high temperature. Flake and crystalline forms of graphite are the most used

in manufacturing of crucibles.

Monoclinic Sulphur

Rhombic Sulphur

- rhombic crystals are short and fat diamond like structures while monoclinic crystals are

long and thin rectangular prisms

- rhombic crystals are formed under 96°C

while monoclinic crystals are formed above 96°C (formed when heating sulphur crystals)

So therefore they can be converted using heat.

C) WHAT ARE SUPHER’S 2 ALLOTROPES???????

C)Monoclinic and

Rhombic

This is a diagram of allotropes.

A. Do Allotropes have high or low melting points and why?????

A. Allotropes have high melting points because their structure is very strong and it is held together tightly. For example you can only break Diamond with Diamond so in other facts you cannot break Diamonds easily.

A. B.

B. Find Diagrams of Sulpher’s Allotropes.

Thanks 4 watching!!!!

By Persia and jaz