Answer:
Convection occurs when particles with a lot of heat energy in a liquid or gas move and take the place of particles with less heat energy. Heat energy is transferred from hot places to cooler places by convection. Liquids and gases expand when they are heated. ... As a result, the particles take up more volume.
Flame (fire) is the effect of a chemical reaction that produces visible light and heat. The chemical reaction is going on in the substance being burned.. Thats why coals glow and flames seem to leap into the air.
<span>If your reaction does not have a flame, then either it is not producing visible light or the reaction does not occur in the air above the substance.</span>