Think of a chemical change as a permanent makeover. When you fry an egg, the heat does something wild to the proteins inside. They unravel, bump into each other, and then lock together in a new shape.
This is why you can’t “unfry” an egg. No amount of cooling will make that cooked white go back to being clear and runny. Compare that to melting a chocolate bar—that’s a physical change; you can just let it cool and it’s solid again. An egg is a loyalist. Once it changes, it stays changed.
The tell-tale signs (that you already know)
If you’ve ever burned toast, you’ve seen another chemical change. The blackened edges? That’s the sugar and starch in the bread carbonizing (fancy word for turning into charcoal). A raw egg and a cooked egg look, smell, and feel completely different. That’s your clue.
Notice the smell? That toasty, almost sulfur-y scent when you overcook an egg? That’s the sulfur compounds reacting. Your nose is a chemical detector—trust it next time you scramble your weekend eggs.
