Playing with fire

Shortly before we started homeschooling, I asked my boy what sort of things he would like to learn about. First on the list was lighting a match. It seems that all kids have a fascination with fire.

According to our science program, the aim of the days lesson was to learn that air is a mixture of gases, and a fifth of air is made up of oxygen. We took a fairly circuitous route to get to that point, though. That particular experiment involves a candle. By chance, the boys had bought scented candles at the markets the day before, so they were pretty much at the front of everyone’s mind. It was a day for candles.

Orange candle

We started off by looking at what a candle really is, and emphasised the point by making one out of an orange. You start by cutting an orange in half through its equator. Take a small knife, and gently scoop out the flesh of the orange. You need to be careful to keep the spike of pith in the middle. Fill your bowl of orange skin with oil, and then light it.

It was neat to be able to show that we were just working with principles. The wax from the candle could be substituted with oil. A cotton wick could become an orange pith wick, and it would all still work. They took ages to light, and were not that bright, but they worked well enough, and were fun.

From previous lessons, he is well aware of the fire triangle. We spent a fair bit of time discussing where our fuel, oxygen, and heat all came from.

Playing around with the oxygen part of the equation, we then looked at how to put a candle out. We started off with the ever popular mixing bicarb soda and vinegar in a cup. This filled our cup with carbon dioxide. Then we lit a candle, poured our carbon dioxide gas over it, and watched it go out.

Big discussions followed. We have just removed oxygen from the fire triangle. Carbon dioxide is heavier than air. Yes, we can do it again.

Oxygen levels

We finally made it to the textbook point of the lesson. We stuck a candle to the bottom of a bowl, added a reasonable amount of water, and then lit the candle. Put a glass over the candle. After a couple of seconds, the candle goes out, and the water level rises about a fifth of the way up the glass.

More discussions. This time about the loss of oxygen, partial vacuums, and why does only some of the air in the glass burn. Yes, we can do that one again as well.

Playing with fireAfter that, we pretty much just moved on to playing with candles and matches generally. The boys learned how to strike matches, as well as just light them off an already burning candle. There was a great deal of different wax melting styles. They practiced lighting one candle from another. They found out that flames always point up, and you can tip a match one way or another, depending on whether you want it to burn faster or slower. There were quite a few burned fingertips working that one out, but never burned badly enough to not want to do it again. They found that if you pull the wick out of a candle, you can replace it with a match if you rub the match in candlewax before lighting it.

Finally, the matches ran out. They had gone through a whole box, so it seemed a reasonable place to stop. Both of them had patches singed off their fringes where they had leaned in for a closer look. It had been a good day.

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About Blokeschool

I am a homeschooling dad with a wife and two boys. I'm not quite sure what I'm doing, so I feel compelled to write it all down. In my spare time, I work as a registered nurse, drink too much coffee, and intermittently renovate the house.
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