Physical Properties: characteristics of matter that can be observed without changing it to another substance. Examples: _________ (mass/volume) ________ (can pulled into wires) __________ (how easy it breaks) __________ (how stretchy) _____________ (lets light through) (Phase change) Density Ductility BrittlenessElasticity Transparency Boiling / freezing points

Physical Changes In a physical change, the substances are not altered chemically. No new products are formed. Chemical bonds are not broken in a physical change. Usually Reversible

Examples Mixtures Change shape Phase changes Make Kool-aid or lemonade Ice to water to steam Ice cream melts Cutting (paper, trees, etc) Break Glass

Physical Change Physical changes might be caused by: – Grinding – Cutting – Crushing – Bending – Breaking – Heating/cooling (change in phase) – squishing

Physical Change Evidence that a physical change has occurred might include: – Change in shape – Change in form – Change in size – Change in phase (This is always a physical change!) Physical changes are usually reversible

Physical change What could you do to these items to cause a physical change to occur?

C hemical P roperties Characteristics of matter that describe its ability to change into a new substance Examples: _________________________ (ability to burn) ___________________(the ability to react with oxygen, which causes apple slices to turn brown and iron to rust) _________________________________(reacts to form new substance) flammability Ability to rust Oxidation Reactivity with acid

A change in matter that results in one or more new substances. You change what it is. Chemical in the original substance combines with another chemical to create a new substance

(2:52) Evidence of a Chemical Reactions

Evidence of Chemical Change New ________appears Bubbbles or ________ Precipitate forms (____ material) _____ is produced ______ is produced ______ is given off Difficult or impossible to __________ color fizzing solid reverse Heat Light Sound