Thursday, February 9, 2012

Burning Flame Needs Air

Last weeks candle experiment was quiet interesting.  My daughter has started reading lecture two in which you learn about the "Brightness of a Flame".  One of the first demonstrations was to show the importance of "fresh air" or oxygen as an element required for the flame combustion reaction to work.  In other words, for the flame to continue burning. 

I gathered what we had around the kitchen like a tall clear drinking glass (the empty jam jar was too short), the bottom of a plastic champagne glass (we used them for a pumpkin mousse dessert over Christmas and fit perfectly as a stand inside the glass), matches, and the number one candle from her 12th birthday cake a month ago:

After putting the candle on the stand we lit the wick and put the glass over the candle:

Then we waited and watched:

Slowly, one of the elements needed starts to be used up.  By covering the candle "we have the case of a candle being put out by the want of air" pg. 33 The Chemical History of a Candle.  Oxygen is required as part of the combustion equation; thus, you start to see the flame disappear:

An explanation of combustion chemistry is much more complicated than this of course; but we enjoyed a simple experiment showing the reaction when one of the elements is eliminated. I quoted the book because I thought you might find interesting, as we did, that Mr. Faraday continues to use the word air rather than oxygen.  When we read through some of these wonderful books, we are aware that the language or terms might be different and even outdated.  This doesn't deter from using these resources though, it actually makes for more research sometimes.  The way in which it is explained with out all the very highly technical and scientific terms that you would find in a text book actually has made this more interesting and reasonable for my 12 year old.  She gets to read the observations of someone whom all this is a wonder and in return she is inspired by that wonder.  As for my part, narrations become essential so that I can catch very minor (or not so minor) things such as the word "air" within the context and explain that it actually refers to an element known as oxygen.  What a perfect place to start a discussion on the periodic table...hmm.


Jedidja said...

Great! I like to read this. And your pictures are so nice. My kids love it.

Melissa said...

Self-motivation is the coolest.

Shirley Ann said...

I really loved reading this. My girls are loving science at the mo. What book are you using BTW?
Love your blog and just had to pass on some blog awards to you ;o) No pressure to take them up though - details on my blog


Grace'n'Chaos said...

I'm stopping by Shirley. We've been using The Chemical History of the Candle by Michael Faraday.