Physical and Chemical Change

Physical Change A change is physical if the reaction: does not make a new product is a change of state eg. Solid to liquid, etc. Eg. Ice melting, cutting grass, ripping a piece of paper

Chemical Change A change is chemical if the reaction: makes a new product (irreversible) produces heat or light produces bubbles of gas forms a precipitate (solid forming on the bottom in a liquid produces a colour change

Physical and Chemical Change To explain whether a chemical reaction is physical or chemical, you may be able to use more than one of the statements For each scenario, call it a physical change (P) or a chemical change (C) and explain why!

Examples YouTube clips:

Examples Frying an egg - C; irreversible, colour change Boiling water - P; change of state, reversible Rotting leaves

More Examples Magnesium burns bright white - C; heat/light given off, irreversible Breaking a piece of chalk - P; no new product formed Dissolve salt in a glass of water - P; reversible (by distillation)