Page 22 - Curriculum Visions Dynamic Book

Charcoal
Charcoal is wood that has been burned at about 1000°C in the absence of air. It is almost pure carbon and consists of tiny crystals of graphite.
Charcoal is able to burn at much higher temperatures than wood, and it is smokeless, so it makes a good fuel.
Activated charcoal is a form of charcoal made by burning waste organic matter (twigs, wood bark, sawdust, etc.) in the absence of air. When it has been processed it has an enormous surface area that is able to absorb molecules of gas.
For this reason it is often used in situations where gas molecules need to be absorbed.
Carbon black
When people are asked what colour they associate with carbon, they usually say black. If people are asked to name a common form of carbon, they often say soot.
In fact black soot (called lampblack) from badly adjusted oil lamps, for example, is almost pure carbon. Pure carbon, a deep black powder, such as is used in photocopiers and laser printers, is obtained by heating anything containing carbon – coal and wood, for example – in
a furnace where there is no air. As a result, coal changes to coke and wood to charcoal.
Powdered carbon contains spheres of the rare form of carbon called buckminsterfullerene. Powdered carbon is used in rubber and plastics
to slow down the rate at which these materials deteriorate in sunlight. Carbon powder is also used to make black ink and paint.
 Charcoal glows when it is heated with
a gas jet from a Bunsen burner. Notice that the charcoal burns without any smoke; all of the graphite crystals are fused together in the charcoal and thus are not released
as soot particles.
 Because it is made from wood, charcoal
is an attractive fuel in the developing world where people need a fuel that provides a high temperature for cooking but where they cannot afford to use electricity, bottled gas or paraffin. Charcoal is also made into briquettes and used for barbecue fires in industrial countries.
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