Question

Why does firewood crackle when it is thrown in a fire?

Asked by: Susannah

Answer

If you have ever "distilled wood", you already know the answer to this question.

Solids and liquids do not burn. First they vaporize to a gas, then the gas burns. When wood is burned, the wood itself vaporizes. Much of this vapor is gaseous wood alcohol and water/steam. If too much vapor is trapped inside the wood, it will exert pressure and cause the wood to pop which causes the crackle.

"Distilling Wood" can be done by heating wood chips in a test tube and condensing the effluent vapor. This produces water, wood alcohol and activated charcoal.

Answered by: Christopher Ingram, B.S., Independent thinker

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10 Ways to Keep Your Kids Interested In Science

Young children are natural scientists: they ask questions, pick up sticks and bugs outside, and are curious about the world around them. But as they get a bit older, many kids gradually lose their interest in science. They might see it as just another task at school, something that doesn't apply to their lives. Of course nothing could be further from the truth, so here are ten ways you can remind your kids that science is everywhere. Most of these are fun for adults, too! Continue reading ...

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