• Question: What is fire?

    Asked by iswiminwaterh2o to Claire, Kate, Matt, Rob, Sam on 21 Jun 2013.
    • Photo: Kate Husband

      Kate Husband answered on 21 Jun 2013:

      Fire is a chemical reaction that gives of heat and light. The flame is the part of this reaction that gives of light, which is why we can see it.

    • Photo: Sam Geen

      Sam Geen answered on 21 Jun 2013:

      Fire is ionised air. An ion is an atom that has had electrons taken away from it. When gas gets hot, the atoms move around very fast, and when they collide, the collisions have enough energy to knock electrons out of the atom. When the electrons join with another atom, they produce light (in fact, this is what light is – electrons emitting energy as they jump up and down energy levels around an atom). The frequency of light is related to its energy, so as the gas gets hotter, the flame has a higher frequency of light. Blue has a higher frequency than red, which is why hotter flames are blue and cooler flames are red. Wood burns because the chemical energy in the plants is released when it gets hot, creating more heat and causing the fire to grow.

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