How is a chemical change different from a physical change?
Answers
In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed.
Physical changes change the shape, size or phase of a substance. Crumpling paper, getting a haircut, dissolving salt in water, melting wax, making ice cubes, chopping veggies for tossed salad, growing crystals from a supersaturated solution, grinding metal and slicing bread are all physical changes.
During a physical change the elements and compounds stay as they are.
Chemical changes make new substances. Cooking an egg rearranges it's proteins. Burning fuels, etching metal with an acid, fermentation, respiration in your cells, decomposition in the compost pile, making zinc iodide in the lab, and forming a silver mirror are all chemical changes.
During a chemical change the elements and compounds get rearranged and recombined into something new.