This has never been asked before on this site, so I thought I would ask this to help future searchers, passerbys, or others understand this better.
What are the key differences between burning something and melting something?
For example, you can burn cake before it melts in an oven, but you can't burn water in a solid state at the same temperature(it will separate the molecules and flow into space; you can't burn H20 either).
So basically, why do some things burn then melt, and some things melt and burn, or do not burn at all?
What does "burn" mean atomically, and what is its relation to melting? They are sometimes used interchangeably to express "burning something", or "melting it" as a greater extreme, despite the fact that ice will melt into water and will never burn, and cake will burn way before melting.
Best Answer
"Burn" and "melt" are completely different things.
"Burning" is a chemical reaction, usually with the oxygen in the air (or any oxidant, really). In organic burning, like the cake you suggested, the carbon compounds react with atmospheric oxygen, producing carbon dioxide, water (vapour) and (sometimes) an ashy residue.
"Melting", on the other hand, is a physical process in which the atoms of the thing you're melting can no longer carry more energy while remaining in the solid state.
The wikipedia articles for Burning ans Melting are pretty self explanatory, to be honest