Properties of MatterSection 2

Physical Properties

• Any characteristic of a material that you can observe without changing the makeup of the material

Examples:ColorShapeSizeDensityMelting PointBoiling Point

Appearance

• Appearance is the most obvious physical property

• Shape, color, and state of matter can be identified just by looking

• They can also be measured

• Volume

• Temperature

• Mass

• Diameter

Behavior

• Behavior is also a physical property

• Examples:

• Magnetism

• Malleable

• Ductile

• Ability to flow

Using Physical Properties to Separate

• Some items can be separated by physical properties

• Sorting by hand

• Sifting

• Using a magnet

Physical Properties

• Can be used to identify substances

• Many physical properties are specific to the material and remain constant and can be used for identification

• Melting point

• Boiling point

• Density

• Specific Heat

Physical Changes

• Any change that does alter the makeup of the material

• You can change size, shape, or state of matter without altering the makeup of the material

• Sometimes physical change can accompany a color change without changing the composition of the material

• Heating a metal until it’s glowing hot

• Sometimes color change accompanies a chemical change

• Rusting

Using Physical Change to Separate

• We can also use physical change to separate materials

• Distillation is a separation technique that allows separation techniques by boiling point

• A mixture is heated until it boils.

• All the material that evaporates at a specific boiling point and be captured when it condenses

• The material that did not boil at that boiling point is left behind

Chemical Properties

• Chemical properties are characteristics of a substance that indicate whether it is likely to undergo a chemical change

• Flammability

• Reactive to light

• Reactivity

• Toxicity

Chemical Change

• The change of one substance into another

• There are several clues that a chemical change is going on

• Rapid release of energy

• Change of heat

• Light

• Sound

• Bubbling

• Color change

• Formation of a solid (precipitate)

Using Chemical Change to Separate

• Silver flatware can become tarnished

• Due to silver reacting with sulfur in the air to make silver sulfide

• The reaction can be reversed by putting the silver in warm water with baking soda and aluminum foil

• In industry and labs, chemical changes like this are used to purify metals

The Conservation of Mass

• During any chemical change, mass is conserved.

• The amount of substance present at the beginning of the reaction will be equal to the amount of substance present at the end of reaction

• Then why does there appear to be less mass after a log burns

• Mass is “lost” as water and gas