Life is not static and neither are chemical or physical properties. But don't let this throw you off, the sign of a change in chemical or physical properties can help you classify them! In a physical change, substances are not altered chemically, but merely changed to another phase. For example, water boiling is a physical change, the change of water in its liquid phase to its gaseous phase. The water is still chemically water (H2O). Chemists would write this as:
H2O (l) --> H2O (g)
Notice how on both the left side and the right side of the arrow water appears. The letters in parentheses () represent the phase of the substance, s for solid, l for liquid, and g for gas.
You will be seeing these symbols used in many chemical reactions we will study.