Re: What exactly causes a flame, I know it's atoms, but how do they ignite?

That's a great question, Sarah, and not an easy one to answer. You are right that a flame is caused by atoms, but it's not directly the burning that causes the flame colour. As chemicals burn they produce energy (this is called an exothermic reaction); this energy excites electrons in the atoms around (that means it gives the electrons extra energy and they move faster); these excited electrons then start to "fall back" down in energy to where they came from and as they slow down they give the extra energy out as light and colours.

Kevin