Out of all the chemical elements—the materials the world is
built of —carbon is one of the most important. An entire branch of
chemistry deals with the thousands of compounds of carbon.
There could not be any living things without carbon. For carbon makes up a part of the living material in every plant and animal. We ourselves are part carbon.
Carbon
is also a part of all our common fuels. Wood, coal, coke, charcoal,
fuel oil, gasoline, and cooking gas all have some carbón in them.
Almost
all our foods contain carbon. In fact, salt and water are the only
things we eat or drink that are not part carbon. Carbon is in many
other substances, too.
Soot and coke and charcoal are almost pure
carbon. From them one would guess that pure carbon is black. Sometimes
it is, but not always. The "lead" in our lead pencils is not really
lead. Instead it is a form of carbon called graphite. Graphite is
iron-gray with a metal-like shine. More surprising, carbon can be clear
and sparkling. For diamonds are carbon!
Vinegar, vaseline, and
silk all have carbon in them. But how different they look! And not one
of them looks at all like diamonds or graphite or soot. In many of the
materials that have carbon in them, the carbon is joined with other
elements to form compounds. In a compound an element may be very well
hidden. Once in a while the carbon in a compound comes out of hiding.
Suppose someone is making candy and lets it burn. The black stuff left
in the pan is the carbon that was once a well-hidden part of the sugar.
