1 (a.c.) Physical and Chemical Changes
Matter is anything that has mass and occupies space. It can have many forms: solid. liquid, and gas. A solid has fixed shape and volume. A liquid has fix volume but no fixed shape. It will mold to its container. A gas has no fixed volume or fixed shape. It will completely fill its container. A physical change is one in which the chemical composition of a substance is unchanged. When ice melts water is going from a solid phase to a liquid phase but they are still water molecules. A chemical change is one at which when the chemical composition of the substance does change. Chemical bonds between atoms must completely break and form to generate completely new substances.