Candle Magic: Two Changes at Once
Identify simultaneous physical melting and chemical burning
What this lesson covers
Why it matters
A burning candle hides two changes at once: wax quietly melting (and re-solidifying) while, up in the flame, wax vapour burns into new gases and light.
Predict first
When candle wax melts near the flame, that part is a…
Melting and re-solidifying wax = physical (still wax). Wax vapour burning to CO₂, water and soot, giving heat and light = chemical (new substances). One candle, both kinds of change.
- physical change — the wax can solidify again — correct
- chemical change — a new substance forms
- not a change at all
What you do
Sort what happens at a burning candle: physical change, or chemical change?
Check yourself
Burning of the wax vapour is a chemical change because…
Combustion makes new substances and releases heat and light.
Melting of the candle wax is a physical change because…
Melted wax is still wax — it can re-solidify, so no new substance forms.
- new substances (CO₂, water, soot) are formed — correct
- the wax only changes shape
- the wax can be recovered unchanged
- the wax can solidify back unchanged — correct
- a gas is produced
- light is given out