2 Physical ChangesAlters form or appearance of matter but does NOT change matter into a different substanceExamples:-Changes of state (solid to liquid, or liquid to gas, etc.)-Changes in shape or form (dissolving, chopping, cutting, bending, breaking, etc)
3 Chemical ChangesA change in matter that produces one or more new substancesChemical change = chemical reactionNew substances have properties different from original substancesExamples:-burning of natural gas on gas stove (combustion)-rusting (oxidation)
5 Law of Conservation of Matter Matter is neither created nor destroyed in any physical or chemical changeNo mass is lost, because during a chemical change, atoms are not lost or gained, just rearranged.
6 Conserving MatterThe idea of atoms explains the law of conservation of matter. For every molecule of methane that burns, two molecules of oxygen are used. The atoms are rearranged in the reaction, but they do not disappear.