1. Chapter 2 Physical Science
Properties of Matter
Chapter 2
Physical Science

2. Section 2.1
Classifying Matter

3. Substances
Substance or pure substance: matter that always has exactly the same composition
Every sample of a given substance has the same properties because a substance has a fixed, uniform composition

4. Element
Element: a substance that cannot be broken down into simpler substances
Atom: the smallest particle of an element
An element has a fixed composition because it contains only one type of atom.

5. What are some examples of elements?
Carbon
Aluminum
Nitrogen
Oxygen
Gold
Tin
Symbol C Al N O Au Sn

6. Compounds
Compounds: a substance made of two or more simpler substances and can be broken down
Always made of the same ratio and type of atoms
H2O is water & H2O2 is hydrogen peroxide
Usually have a different appearance from the elements they are made of
Examples: salt, sugar, water
A compound always contains two or more elements joined in a fixed position.

7. Mixture
Mixture: a material made up of two or more substances that can be separated by physical means
Do not combine chemically
Example: saltwater, cheerios & milk, air
The properties of a mixture can vary because the composition of a mixture is not fixed

8. 2 Types of Mixtures
1. Heterogeneous mixture: have materials that are not evenly distributed and noticeably different from one another
Granite, concrete, pizza, dry soup mixes, salad dressing
2. Homogeneous mixture: have materials that are evenly distributed so it is difficult to distinguish one substance from another
Also called a solution
Remain constantly and uniformly mixed
Which type of mixture is milk?

9. Based on the size of it’s largest particles, a mixture can be classified as a solution, a suspension, or a colloid.
In Your Notebook
1. Define : (Use pages of your book)
Solution
Suspension
Colloid
2. Provide examples of each.
3. Identify what type of mixtures they are.
4. Describe how they are different from each other.

10. Solutions
Solution – when substances dissolve and form a homogenous mixture
Examples: windshield wiper fluid, sea water, lemonade

11. Suspensions
Suspension – a heterogeneous mixture that separates into layers over time.
Examples: muddy water, vinegar and oil, fresh milk (cream is suspended)

12. Colloids
Colloid – contains some particles that are larger than those in a solution, but smaller than those in a suspension.
Examples: homogenized milk, fog
Think about it… What happens to the size of the drops of fat in milk when milk is homogenized??

13. The Scattering of Light
Colloids and Suspensions scatter light just like fog.
Light goes right through a solution.

14. Section 2.2
Physical Properties

15. Physical Properties
Characteristics you can observe or measure without changing the composition of the substance
Viscosity, conductivity, malleability, hardness, melting point, boiling point, and density are examples
Can be measured
Can be used to choose a material for a specific purpose, identify materials, or to separate materials from each other
What properties would you expect a material used for a pot holder to have?

16. What do these terms mean??
Viscosity
Resistance to flowing – corn syrup
Conductivity
Ability to allow heat to flow
Malleability
Ability to be hammered without shattering

17. What do these terms mean?
Hardness (Which substance is the hardest known?)
Diamond
Density
Ratio of mass to volume

18. How Physical Properties are Used
Identification – Archimedes and the crown
Material Choice – would you want to use rubber to make beams for a skyscraper? Why pick wax to make molds?
Separation of mixtures
Filtration – separates materials based on the size of the particles
Distillation – separates substances based on boiling points. Can separate a liquid and a dissolved solid (sugar water)

19. Physical Changes
Physical change occurs when some of the properties of a materials change, but the substance in the material remains the same
Paper
Tomatoes
Water

20. Section 2.3
Chemical Properties

21. Chemical Property
A characteristic that can cause it to change its molecular makeup
Examples: flammable, combustible, react with light
Chemical change: a change from one substance to another substance
Fireworks explode, matches burn, frying an egg, iron rusting
Different substances can be produced

22. Chemical Properties
Any ability to produce a change in the composition of matter
Chemical properties can be observed only when the substance in a sample of matter are changing into different substances.

23. Chemical Properties
Flammability – the ability to burn in the presence of oxygen
Reactivity – how readily a substance combines chemically with other substances
A chemical change
occurs when a substance
reacts and forms one or
more new substances.

24. Chemical Changes
Three common types of evidence for a chemical change are a change in color, the production of a gas, and the formation of a precipitate.
What is a precipitate?
Any solid that forms and separates from a liquid in a mixture.

25. Chemical or Physical
When matter undergoes a chemical change, the composition of the matter changes.
When matter undergoes a physical change, the composition of the matter remains the same.
Rusting? (Hint: Iron & Oxygen are both highly reactive)
Melting?