Reviewing MATTER
 Matter: anything that has mass and volume
 Mass – the amount of matter in something
 Volume – the amount of space something occupies


Physical and Chemical Properties of
Matter
Why do I care? Understanding the different properties of matter will help you to better classify and describe the world around you.

 Property: a characteristic of a substance that can be observed
 It can be a physical or chemical property.

- A property that can be observed and measured without changing the material’s composition.

EXTENSIVE Physical Property
Extensive - Properties that depend on the amount of matter present.
• Mass - A measurement of the amount of matter in a object (grams).
• Weight - A measurement of the gravitational force of attraction of the Earth acting on an object.
• Volume - A measurement of the amount of space a substance occupies.
• Length

 Look at your pencil or pen, if you break it in half, the extensive properties will be different.
 The pieces will have a different mass, weight, volume, and length.
 Extensive properties depend on size


Intensive - Properties that do not depend on the amount of the matter present.
 Color
 Odor
 Luster
 Malleability
 Ductility
 Electrical Conductivity
 Hardness
 Melting/Freezing/Boiling Points
 Density
 State of Matter

 Look at your pencil or pen, if you break it in half, the intensive properties will be the same.

It’s still yellow, the graphite still has a hardness of 2, the density of each piece hasn’t changed, and it’s still a solid.
 Intensive properties DON’T depend on size

 Chemical property: a property that can only be observed by changing the composition of the material.
 Does it have the potential to change into a new substance?
Examples:
• Will it burn?
•Will it rust?
•Will it react with vinegar
(acids) or other chemicals?

Physical and Chemical Properties can be used to identify matter

Gold or fool’s gold?
 Diamond or quartz?
 Oak or Maple?
 Metamorphic or
Igneous?
 Zinc or Aluminum?
http://www.youtube.com/watch?v=uJ
OGy0dgmUU
Properties song

Changes in Matter
 Change: the act of altering a substance
 In science, we talk of two types of changes: physical chemical

 Physical change: a change that occurs that does not change the identity or make up of the substance
 Change in state or phase (Freezing, boiling, melting, sublimating)
 Changing shape (cutting, folding, twisting, bending)
 Dissolving



Physical changes are changes that alter the size, shape, location or physical state of a substance but not its chemical state.
Its still H
2
O- frozen in snowflakes, as liquid in raindrops, or as a gaseous water vapor, it’s chemical formula has not changed.

 A physical change in a substance doesn't change what the substance is.
 Cutting, folding, or crumpling paper –
 A physical change in the shape and size of the paper. However, it is still paper!
 Dissolving sugar in iced tea-
 Sugar is still C
6
H
12
O
6 but now it is spread out in the liquid, it still tastes just as sweet!

 Cutting
 Tearing
 Shredding
 Shrinking
 Enlarging
 Change in Phase
 Relocating
 Rotating
 Molding (shaping)

 Chemical change: a change that occurs causing the identity of the substance to change
 Burning
 Chemically digesting food (acid and bile)
 Reacting with other substances
 A chemical change is also called a chemical reaction

Chemical Changes
 Chemical changes are changes that alter the chemical make up of the substance.
 New matter is formed with properties that are different than those of the original matter.

Chemical Changes
 If you end up with a chemical or chemicals that you did not start with. . .
 It is a chemical change!

Chemical Changes
 A chemical change is not easily reversed.
Easy to reverse/change back
Difficult to reverse/change back

 Creation of a gas (bubbles)
 Creation or loss of heat
 Fire
 Rotting/molding
 Breaking down (decomposition)
 Precipitation (Sour milk clumps)
 Cooking
 Rusting (oxidation)

Heat and light are often evidence of a chemical change.

The strike of a match is a chemical change due to the reaction of the chemicals with oxygen.

Burning wood turns to charcoal and ashes.
This is a chemical change .

Chemical Change
Melting cheese
Burning wood
Milk souring
Folding up paper
Bicycle rusting
Physical

 Physical and
Chemical changes occur around us everyday!
Understanding them will help us better understand our world.

 Start physical changes challenge Powerpoint