1. Classification of Matter

2. Classification of Matter
Scientists like to classify things
Scientists classify matter by its composition
All matter can be classified as a substance or mixture

3. Why isn’t it a good idea to classify matter by its phases?
Because one kind of substance can exist in more than one phase – such as H20.

4. Why isn’t matter classified according to physical characteristics such as color?
Scientists wouldn’t find it very useful to group gold, sunflowers, and the sun together.

5. Classification of Matter
All matter has properties
Properties are used to classify matter
ALL matter is made of a pure substance or mixture of substances

6. Substances Substance Type of matter with a fixed composition
All substances are built from atoms
Atoms are the smallest part of matter
2 types of substances
Elements
Compounds

7. Elements Elements Consists of only one type of atom
Can’t be broken down into simpler substances
Chemists use symbols to recognize elements
These are found on the periodic table of elements

8. Elements Elements Examples Oxygen Carbon Hydrogen Iron Neon Copper
Nitrogen
Mercury

10. Compounds Compounds Two or more elements combined Fixed proportion
Can’t be broken down by physical means only chemically

11. Compounds Compounds Examples Water (H₂O) Salt (NaCl)
Carbon Dioxide (CO₂)
Carbon Monoxide (CO)
Glucose (C₆H₁₂O₆)

12. Mixtures Mixtures Made up of two or more substances
CAN be separated by physical means
4 types of mixtures
Homogenous
Heterogenous
Colloids
Suspensions

13. Homogenous Mixtures Homogenous
Contains two or more substances blended evenly throughout
Also called solutions
Characteristics:
Blended evenly
Particles will not settle
Can’t see individual particles within the solution
“Well mixed”

14. Homogenous Mixtures Homogenous Mixtures Examples Gatorade
Bottled Soft drinks
Kool-Aid (well mixed)
Vinegar
Brewed coffee

15. Heterogenous Mixture Heterogenous Mixture
Materials can be easily distinguished
Characteristics
Not mixed evenly
Some can be hard to detect
Most substances are heterogenous

16. Heterogenous Mixture Heterogenous Mixtures Examples Pizza
Chicken noodle soup
Concrete
Dirt/Soil
Cereal
Drinks with ice

17. Colloids Colloid Examples Special kind of mixture
Has both homogenous and hererogenous qualities
Characteristics
Particles are suspended but won’t settle
Particles are bigger than those in solutions
Will produce tyndall effect (scattering of light)
Examples
Milk
Fog
Paint

18. Colloids
Tyndall Effect

19. Suspensions Suspensions Heterogenous mixture Characteristics Examples
Particles big enough to see
Particles will settle to bottom
Examples
Muddy water
Italian salad dressing

20. Suspensions

21. Characteristics of Mixtures

23. Properties of Matter; Physical and Chemical
Physical Properties
Characteristic of a material you can observe
Examples:
Color
Size
Shape
Density
Melting point
Boiling point

24. Physical Properties Physical Property
Appearances of matter are physical properties
Appearance:
Shape
Color
State of matter (solid, liquid or gas)
Odor
Mass
Volume
What are some physical properties of the liquid in the image below?

25. Physical Properties Physical Properties
Behavior of matter are also physical properties
Behaviors
Magnetic
Malleable (stretch or bend)
Ductile (drawn into wire)
Ability to flow easily (soft drink versus syrup)

26. Physical Change Physical Change
A change in size, shape or state of matter
The identity of the material doesn’t change
Examples
Tearing a piece of paper
Breaking glass
Painting a wall
Liquid freezing
Solids melting

27. Chemical Property Chemical Property
Characteristics that indicate whether it can undergo a chemical change
Examples
Flammability
Certain medicines reacting to light

28. Chemical Changes Chemical Changes Physical or Chemical Change?
A change from one substance to another
A new substance has formed
Can’t reverse effects
Examples
Cooking an egg
Rust
Burning
Rotting food
Physical or Chemical Change?
Physical Or Chemical Change?

29. Separating Mixtures
Can use physical properties to separate mixtures into its components
Distillation
Uses boiling point to separate components of liquids

30. Law of Conservation of Mass
During a chemical change, matter is not created or destroyed
Mass before chemical change equals mass after chemical change

31. Video Clips for Review Physical and Chemical Properties
Chemical Versus Physical Changes