Matter forever!
After a log burns in a fireplace, only a few handfuls of soft ashes are
left. Most of the matter in the log seems to be gone. But is it really
gone? No! It has simply changed into other kinds of matter.
Wood is made up of molecules, like all other matter. So, when the wood
burns, the heat makes the molecules speed up and begin to break apart.
Most of the atoms from the broken-up molecules combine themselves into
different kinds of matter. Some atoms form molecules of gases that
escape into the air. Other atoms
form molecules of water—but because the water is very hot, it quickly
becomes a gas and escapes, too. A few atoms don’t get quite hot enough
to form molecules of gas. They are carried off as smoke.
Some kinds of molecules in the log just don’t burn—the heat doesn’t
break them apart. Those molecules are easy to find! They are the ashes
left when the rest of the wood has burned.
Any kind of matter can be broken up and rearranged into other kinds of
matter. But when this happens, the atoms and molecules in the matter
don’t really get used up. They are still around, if you know where to
look!
