Asked by: Toby Graham, Shrewsbury
The nature of a flame depends on what is being burnt. A candle flame will primarily be a mixture of hot gases (air and vaporised paraffin wax). The oxygen in the air reacts with the paraffin to produce heat, light and carbon dioxide. Other materials – such as magnesium – burn much hotter, resulting in the fourth state of matter: plasma.
Read more:
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun facts.