Chemical Properties (opposite of physical properties)
Chem. Prop. Cannot be observed WITHOUT changing the substance. Combustion—matches have to be burned in order to determine if they are combustible. The match is then changed forever.
Physical Change Change in the form or appearance of the matter but not its composition. Ex: changing shape—wadding paper. dissolving—still taste the sugar in the tea. They haven’t changed changing state—ice is still water condensation, vaporization, sublimation,
Vaporization Changing of a liquid to a gas Includes boiling and evaporation (different temperatures)
Freezing vs Melting Freezing—liquid to solid Melting—solid to liquid Both occur at the same temperature for a substance (water @ 0 degrees)
Chemical CHANGE 5 SIGNS OF A CHEMICAL CHANGE (NOT ALL ARE REQUIRED) Color change—apple turns brown 2. Energy released or gained—gets hot or cold New odor—eggs rotting Gases or solids created—smoking, bubbling, precipitate Not easily reversed—can’t turn water into hydrogen and oxygen
Chemical vs. Physical Change A physical change retains the original substance. A chemical change changes the substance into something NEW.
Law of Conservation of Mass The particles in matter can be rearranged but the mass of the matter ALWAYS remains the same before and after a chemical OR physical change.