When a candle is lit, a combustion reaction takes place that releases heat, this heat causes the temperature of the candle to increase and the state of the candle to be liquid. Molecules move due to heat.
When the candle blown out, the temperature begins to decrease and the liquid wax begins to solidify because the molecules move slower and slower. Therefore, the spaces of the obtained can be filled in the following way:
When the candle was blown out the wax solidifies because the molecules have low energy and moved slower.
