HOW YOU CAN DISCOVER WHAT AFLAME IS
Gather these materials: A wooden match;a waxtaper;a smallcandle;a
cigarettelighter;a pieceofpaper;and4 clean cool saucers from the kitchen.
(Obtainyourmother'spermissionto use the saucers.)
Follow this procedure:Strike the match. Holdthe yellowpartofthe flame
closeunderthebottomofoneofthe saucers.Noticewhathappens.Blow the
matchoutandexamine theundersideofthe saucer for moisture.Lightthe wax
taper. Holdtheyellow partofthe flame close to the underside of the next
saucer.Blowoutthetaperandexamine the saucer. Follow the sameprocedure,
using the candleandthecigarettelighter.
Results:Whenever the yellowpartofa flame came incontactwith a cool
dish, a blacksubstancewas deposited. Thissubstanceis carbon.Whencarbon
burnsincompletely, which is usually the case,itglows with a yellow color. A
flame is madeoftiny particlesofvery hotcarbon.When they cool quickly, as
they did onstrikingthe cool dish, they weredepositedthere as blackcarbon.
When they cool more slowly, as above an open flame, theyjoinwith atomsof
oxygen from the air and becomecarbondioxide(C0 2 ) ,a colorless invisible gas.
Youfoundthebottomof the saucers damp. Every flame gives off watervapor
also. This is because the fuelcontainshydrogen, which combines with oxygen
in the air to form water vapor. Wherever there is a fire then, there iscarbonin
the flame, and there are twoby-products-carbondioxideandwater vapor.
Anythingthatwillburnup can be called afuel, and all fuels havecertain
chemicalcharacteristicsincommon.Mostof themcontaincarbon,hydrogenor
both.They are usuallyorganic hydrocarbons.The word"organic"meansthat
thesubstancewas once alive. Wood, for example, was once a tree. Coal comes
fromwhole foreststhatwere alive many eons ago.Charcoalalso comes from
wood, but in a different way. Oil, kerosene, benzine, even wax, all come from
petroleum,which inturncomes from smalldropsofoil in the bodiesoflong-