1. Physical & Chemical Properties/Changes

2. Learning goals
We are learning the difference between physical and chemical properties.
We are learning the difference between physical and chemical changes.

3. Recall Matter is the “stuff” that something is made up of.
It has a mass and it occupies a volume.
Matter can be broken down into simpler units, the simplest being the atom.

4. Classification of Matter
PURE SUBSTANCES
MIXTURES
ELEMENTS
i.e: H, O, C
COMPOUNDS
i.e: H2O, NaCl
HOMOGENOUS
(solution)
i.e: H2O + salt
HETEROGENOUS
(Mech. Mixture)
i.e: H2O + raisins
Can combine to form

5. Physical Properties
Properties that can be observed using our 5 senses.

6. Examples include: State (solid, liquid or gas) Colour
Texture (rough or smooth?)
Lustre (shiny or dull?)
Clarity (clear, cloudy or opaque?)
Viscosity (how well does it flow? viscous or less viscous?)
Hardness (easily scratched?)
Malleable (can it be hammered into sheets or molded?)
Ductile (can it be pulled into a wire?)
Electrical conductivity (does electrical current flow through it?)
Density (amount of mass per volume)

7. Types of Physical Properties
Quantitative: physical properties that can be measured:
i.e: Boiling point, melting point, density
Qualitative: physical properties that can only be described.
i.e: Color, shape, texture

8. Chemical Properties
describe how a substance reacts in the presence of another.

9. Changes!

10. Physical & Chemical Changes
Physical changes: No new substance is produced.
Chemical changes: Starting substance is changed to something with new properties not seen before.

11. Physical Changes Change in SIZE (cutting a gold block in half)
Change in SHAPE (making a paper airplane)
Change in STATE (ice cube melting)
Making a SOLUTION (salt dissolved in water)
No new substance is made, and all changes are reversible.

12. Chemical Changes
Change in COLOUR (iron nail producing red rust)
Change in ODOUR (garbage rotting)
Change in TEMPERATURE (cold pack)
LIGHT IS GIVEN OFF (fire-fly)
BUBBLES OF A GAS are formed (bubbles not caused by heat)
NEW SOLID is made from mixing two solutions (precipitate)
Chemical changes are difficult or impossible to reverse.

13. Learning goals
We are learning the difference between physical and chemical properties.
We are learning the difference between physical and chemical changes.

14. Try this … physical or chemical change?
Iron rusts
NaOH dissolves in water
Match ignites and burns
Cube of ice melts to form a puddle of water
Water is heated and changes into steam
Chocolate bar melts in sun
Vinegar and baking soda react