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Interactive Chemistry Worksheets for Students


Periodic table

Naming compounds

Basic formula

Simple compounds

Ionic compounds 1

Ionic compounds 2

Chemical suffixes

Old chemical names

Hydrocarbons - Alkanes

Alkanes, alkenes & alkynes

Alkanols to alkanoic acids


Common compounds

Common formula quiz

Acids, bases and salts

Covalent compounds

Printable worksheets


A wedding ring of soot?

Diamond, graphite and soot are all made of carbon atoms. So on your wedding day why not save money and buy a cheaper wedding ring made from soot?

Well, you may need to learn a bit of chemistry to help your marriage survive!

The chemical formula of diamond is C which is the chemical symbol for the element carbon. Soot and graphite are also made up of carbon atoms and have the same chemical symbol, C. So what's the difference between soot, graphite and diamond if they are all made up of the same carbon atoms?

Carbon atoms can be arranged in many different physical forms called allotropes.

An allotrope is a form of an element that has different physical properties (eg. color, crystal shape, hardness, melting points,  boiling points, etc.) due to different arrangements of atoms or molecules within the structure.

Four allotropes of carbon are diamond, buckminsterfullerene (bucky balls), graphite and soot. Since all are forms of the element carbon, they each have the same chemical symbol C.

The allotropes of carbon however, differ greatly in their structure and properties.

In diamond the carbon atoms are covalently bonded to one another producing a three dimensional network solid. Each carbon atom is bonded to four other atoms throughout the crystal lattice.

Diamond has no free electrons because they are all involved in bonding and is therefore a poor conductor of electricity.

Diamond is the hardest substance known and is used to cut glass and in industrial drill bits. Diamond is widely sought after because of its rarity and unique crystalline structure and is used in jewelry.

Graphite is also made of carbon atoms. Graphite consists of carbon atoms covalently bonded together in a layers made up of hexagons, like chicken wire.

Each carbon atom has three bonds and one free electron. The extra electrons are delocalized and can be moved along the layers by applying an external voltage. This is why graphite can conduct an electric current.

Graphite unlike diamond is extremely soft. Between the parallel layers of graphite are weak intermolecular bonds, which allow the layers to easily slip over each other. This is what happens when writing or drawing with a graphite pencil on paper.

Buckminsterfullerene (a bucky ball for short) is an allotrope of carbon that is produced by firing high powered laser beams at graphite. Each molecule consists of a large number of carbon atoms covalently bonded to one another forming a sphere (similar to a soccer ball).

Soot has no crystalline structure and is amorphous in form. It is a carcinogenic (cancer forming) pollutant produced by the incomplete combustion of hydrocarbons, particularly gasoline or petrol and diesel fuels.

So the key to a successful marriage is to buy the correct allotrope of carbon for a wedding ring. It's not just the atoms that are important. It's how they are arranged!