ACS: The Secret Science of Stuff - The Secret Science of FLAMES

Why does blowing on a flame make it go out?

The answer could be a few different reasons.

  • Your breath has a lot of carbon dioxide. When you blow, the carbon dioxide pushes oxygen out of the way and the flame goes out.
  • Your breath blows away some of the hot air around the flame. If the liquid wax cools down enough, it can’t become a gas. Without wax gas, the flame won’t burn.
  • Your breath blows some of the wax gas away. Without this fuel, the flame will go out.

Why does a flame have different colors?

The colors of a flame are caused by bits of wax molecules that didn’t get completely reacted. These glow a certain color when they get to be a certain temperature. Since different parts of the flame have different temperatures, these bits of wax molecules make those areas of the flame glow with different colors.

How do candles with different colored flames work?

There are some special types of candles that have flames of different colors.  These candles are made by adding certain chemicals to the wax. When they get hot enough, these chemicals glow a particular color like red, green, purple, or blue. Here, there is a regular candle in the middle and special color-flame candles on either side.

Science Topics
Chemistry, Heat
Kindergarten, 1st Grade, 2nd Grade, 3rd Grade, 4th Grade, 5th Grade
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