deaddiatoms,microscopiccreatures(hatlive in water. The word"hydrocarbon"
means asubstancethatcontainshydrogen andcarbon.
Burning iscombustion, and combustionis a type ofoxidation. Oxidation
means becoming combinedchemically with oxygen. Oxidation is a type of
chemicalreactioncalledexothermic,meaningthatthereactiongives off heat
energy.Exo-is a prefix meaning"out."The root,thermic,comes from a Greek
word meaning"heat."Some chemical reactions do not giveoutheatbutinstead
require thatit be added. These are called endothermicreactions. Endo-is a
prefix meaning"in."
Now let us see the chemicalequations for the oxidationofcarbonand
hydrogen:
C+Oz~COz(Thisreactionoccurs whenthereisenoughoxygen for the
formationofcarbondioxide.)
2C+Oz~2CO (This reaction occurs when there is only enough oxygen
for theformationofcarbonmonoxide, apoisonous gas.)
2Hz+O,~2HzO
These reactions give off the energy you feel and see asheatandlight.
WHATARE THE DIFFERENT PARTS OF AFLAME?
Gather thesematerials:Aratherlargeplumber'scandle;an alcoholburner;
and a IO-inch piece of glasstubingdrawn out to a fine nozzle at one end.Obtain
yourmother'spermission to use the gas stove. If your familydoesn'thave a gas
stove, you will have to omit thepartsoftheexperimentthatrequire it.
Follow this procedure:Light the candle, the alcoholburner,and the gas stove.
Comparethe three flames.Noteany differencesthatyou see. Now place the
end of the glasstubingwith the larger opening in the center of the candle flame,
right next to the wick. After a few seconds, try to light the gas escaping from
the nozzle end of the tube.Recordthe result. Follow the sameprocedurewith
the alcohol flame and then the gas flame. In each case, be sure toputthe tube
in the centerofthe flame.Compareall the results.