Properties of Matter All forms of matter have properties. Examples: hardness, texture, odor, color, flammability, etc. Two categories: pure substance -made of only one kind of material and has definite properties mixture -two or more substances mixed together but not chemically combined ex: concrete, salt water -solutions – best mixed of all possible mixtures ex: sugar water

Properties of Matter elements – pure substances that cannot be broken down into other substances by any chemical means elements can be chemically combined to form compounds ex: hydrogen, oxygen.. Periodic Table compound – a pure substance formed from chemical combinations of elements compounds have different properties from the elements that formed them ex: water (H2O), carbon dioxide (CO2)

Properties of Matter characteristic property – a property that always holds true for a substance characteristic properties never change, they can be used to identify unknown matter. ex: boiling & melting points Comparing boiling and melting points can be used to identify different substances.

Properties of Matter physical property -characteristics of a substance that can be observed without changing the identity of the substance ex: color, size, texture, density, volume & mass physical change: -a change in any physical property of a substance, not in the substance itself

Phase change - Physical When matter changes from one form to another, the substance does not change. Only the arrangement, space and movement of molecules. Define the following: -melting -freezing -boiling -evaporation -sublimation -condensation -deposition

Phase change - Physical melting- solid becomes a liquid (particles gain energy) *melting point- temp at which a solid begins to melt freezing- liquid becomes a solid (particles lose energy) *freezing point- temp at which a liquid begins to freeze ***melting and freezing point of a substance are the same***

Phase change - Physical boiling- liquid becomes a gas (produces bubbles) *boiling point- temp at which a liquid begins to turn to gas evaporation- liquid becomes a gas (occurs at surface of a liquid) sublimation – solid changes directly to a gas ex: dry ice (solid CO2) – turns to gas

Phase change - Physical condensation- gas changes to a liquid deposition- gas changes directly to a solid “The Chem Life”

Properties of Matter chemical property -describes how one or more substances can form new substances ex: combustibility, rusting and tarnishing chemical change: -when one or more substances change into a different substance -combinations of atoms rearrange to make new substances

Properties of Matter production of an odor- some chemical changes produce new smells change in temperature- chemical changes often are accompanied by a change in temperature (increase or decrease) change in color- a change in color often indicates a chemical change (color change will not be reversible) formation of bubbles- the formation of gas bubbles is an indicator that a chemical change has occurred formation of a solid- when two liquids combine, a solid called a precipitate may form, indicating a chemical change

Properties of Matter Pop Quiz Decide whether each statement describes a physical or chemical change. A bicycle left out in the rain begins to rust. A match burns, leaving only a charred stick of wood. A copper wire is cut into five smaller pieces. An ice cube melts. A glowing splint placed in a test tube causes a loud “pop”. Food coloring is added to cake icing to make it pink.

Properties of Matter Pop Quiz Gasoline burns in a car engine. Antifreeze is added to a car radiator to lower the freezing point. A spoonful of sugar is dissolved in cup of coffee. A silver knife and fork tarnish when they are exposed to air for several weeks. Leaves of a maple tree turn bright red as winter approaches. A water molecule gains enough energy to enter the vapor phase.