Carbon ChemistryCarbon Chemistry8th Grade ChemistryMs. Mudd

Properties of CarbonProperties of Carbon

Key concepts Key Terms

How is carbon able to form such a huge variety of compounds?

What are four forms of pure carbon?

DiamondGraphiteFullereneNanotube

Carbon Atoms and Carbon Atoms and BondingBondingThe atomic number of carbon is 6, which

means the nucleus of a carbon atom contains 6 protons.

Surrounding the nucleus is 6 electrons.Four are valence electrons-electrons

available for bonding.A bond is a chemical force that holds two

atoms together.Two atoms gain, lose, or share valence

electrons in a way to make the atoms more stable.

The transfer or sharing of valence electrons creates chemical bonds.

Atoms of most elements form chemical bonds.

Carbon Atoms and Carbon Atoms and BondingBondingCarbon is unique.Few elements have the ability of carbon to

bond with both itself and other elements in so many different ways.

With four valence electrons, each carbon atom is able to form four bonds.

It is possible to form molecules made of thousands of carbon atoms.

By comparison, hydrogen, oxygen, and nitrogen can only form one, two, or three bonds.

Carbon atoms can form straight chains, branched chains, and rings.

Sometimes two or more rings can join together.

Forms of Pure CarbonForms of Pure CarbonBecause of the ways that carbon

forms bonds, the pure element can exist in many forms.

Diamond, graphite, fullerenes, and nanotubes are the four forms of the element carbon.

DiamondDiamond The hardest mineral, diamond, forms deep within

Earth. At very high temperatures and pressures, carbon

atoms form crystals. Each carbon atom is bonded strongly to form

other carbon atoms. The result is a solid that is extremely hard and

nonreactive. The melting point of diamond is more than 3,500

C˚- as hot as some stars. Diamonds are prized for their brilliance and clarity

when cut as gems. Chemists are able to make fake diamonds, but

they are not considered beautiful enough to use as gems.

Diamonds work well in cutting tools, such as drills.

Fullerenes Fullerenes In 1985 scientists made a new form

of carbon.It consists of carbon atoms arranged

in the shape of a hollow sphere.This form of carbon was named

fullerene, for the architect Buckminster Fuller, who designed dome-shaped buildings called geodesic domes.

One type of fullerenes has been nicknamed “buckyballs.”

GraphiteGraphiteVery time you write with a pencil, you leave a

layer of carbon on the paper.The “lead” in a lead pencil is actually mostly

graphite. In graphite, each carbon atom is bonded

tightly to three other carbon atoms in flat layers.

The bonds between the layers are very weak, so the layers slide past one another easily.

If you run your finger over the pencil marks, you can feel how slippery graphite is.

This also makes it a great lubricant in machines.

Graphite reduces friction between the moving parts.

NanotubesNanotubes In 1991, another form of carbon was made-the

nanotube. In a nanotube, carbon atoms arranged in the

shape of a long hollow cylinder, or tube. You can think of a nanotube as a sheet of graphite

rolled into a tube. Only a few nanometers wide in diameter,

nanotubes are tiny, light, flexible, and extremely strong.

Nanotubes are also good conductors of electricity and heat.

Scientists are looking for ways to use the unique properties of fullerenes and nanotubes.

Possibly delivery of medicines molecules into cells. Conductors in electronic devices and super strong

cables.