In this activity, students take a closer look at a candle flame as an example of a flame that occurs in most natural fires and observe and investigate the flame and the process of burning.
By the end of this activity, students should be able to:
- appreciate the importance of observation (seeing and describing, not just looking) for scientists.
- identify the components of a diffusion flame (in a candle)
- develop ideas about the combustion process – the candle wax is melting, becoming a liquid, then the liquid vaporises into a volatile gas, which ignites when at ignition temperature.
- understand that the white smoke contains these volatile gases
- understand that black smoke contains unburnt particles – soot
- understand that fire needs oxygenheat and fuel – depriving a fire from oxygen causes extinguishment.
Download the Word file (see link below) for:
- introduction/background notes
- what you need
- what to do.
Nature of science
Scientists observe phenomena very closely and carefully – seeing and describing everything – to help them understand what is happening.
Related content
Fire, as a context for learning, covers key science concepts in chemistry. The article What is fire? explores the fire triangle and What is smoke? explains incomplete combustion and the dangers that smoke presents.
Activity ideas
The great candle experiment – the oft-used inverted jar in a saucer of water but without the common misconceptions.
Other teacher resources include Alternative conceptions about fire and Fire – unit plan. Read about how two year 7–8 teachers used various fire resources, including this activity, to teach a cross-curricular unit combining science, English and ethics.
