1. Matter can be classified as mixtures or pure substance Chapter 7
Grade 7 Science Unit 3
Matter can be classified as mixtures or pure substance
Chapter 7 1

2. The Story of Archimedes
*Read Story

3. Review: Particle Theory of Matter
All matter is made up of tiny particles.
These particles are always moving... they have energy
There are spaces among particles.
There are attractive forces between the particles.
The particles of one substance differ from the particles of other

4. Mini-Partner Activity 1
Together think of examples for each, then answer the following 2 questions.
Pure Substance
Mixture

5. 1. How would you tell the difference between a pure substance and a mixture?
____________________________________________________________________________________________________________________________________________________________________________________

6. 1. How would you tell the difference between a pure substance and a mixture?
__See (the properties) if you can see the different parts, (different states, different_ colour, texture, etc). A pure substance should be the samethroughout____________

7. 2. How would use the Particle Theory of Matter to support your answer to question #1?
____________________________________________________________________________________________________________________________________________________________________________________

8. 2. How would use the Particle Theory of Matter to support your answer to question #1?
___A pure substance has its own kind of particle, that are different than___ other substances particles. That____ means it should have the same____ properties throughout___________

9. Mixtures Vs. Pure Substances
How many visible Parts?
Mixtures
Pure Substances
May have more than one visible part (not always - think salt/sugar water)
Have ONLY one visible part

10. Mixtures Vs. Pure Substances
Uniform Througout?
Mixtures
Pure Substances
MAY appear uniform throughout.
ALWAYS appear as uniform throughout

11. Mixtures Vs. Pure Substances
Definition?
Mixtures
Pure Substances
They are the physical combination of two or more pure substances.
They contain either a single particle or two or more atoms chemically combined to form a different substance.

12. Mixtures Vs. Pure Substances
Examples
Mixtures
Pure Substances
•salt water,
•kool-aid
•chocolate chip cookie
•muddy water
•salad dressing
•air
•sugar (C12H22O11)
•gold (Au),
•copper (Cu)
•distilled water (H2O)
•carbon dioxide (CO2)
•oxygen (O2)

13. Mixtures Vs. Pure Substances
Drawing of Particles
Mixtures
Pure Substances
*Can be this, just as long as all the particles are the same throughout

14. Mini-Partner Activity 2
Read pages 232, 236, and 237.
Make a list of solutions and mixtures that you encounter in a day.
Put a * those that may pose a safety risk.

15. Soltions Vs. Mixtures!
Solutions
Mixtures

16. Practice Questions (Homework) Pg 237 Q’s 1,2 &3

17. Read Page 242 - Complete the Following Flow Chart

18. Homogeneous vs. Heterogeneous Mixtures
Also called?
solutions
also called
mechanical
mixtures

19. Homogeneous vs. Heterogeneous Mixtures
States of Matter?
solid,
liquid or gas
can be solid,

20. Homogeneous vs. Heterogeneous Mixtures
Particles?
the particles are evenly mixed none of the original substances are visible
the particles do
not evenly mix

21. Homogeneous vs. Heterogeneous Mixtures
# of visible parts?
they appear
to be ONE
substance
the different parts are visible to the eye (may need a microscope)

22. Homogeneous vs. Heterogeneous Mixtures
How does light pass?
light passes
through
unaffected
Light will reflect
Perpendicular to the direction of the beam

23. Homogeneous vs. Heterogeneous Mixtures
Examples
Kool-aide
Salt water
Vegetable oil
Pure air
Stainless steel frying pan
Granola Bar
Concrete
Beach
Salad Dressing
Computer
Smog-filled air

24. The Tyndall Effect
Light can be used to distinguish between solutions and what appears to be a solution
•cannot be used to distinguish between a solution and a pure liquid

25. The Tyndall Effect In a Solution/homogeneous: Light passes unaffected
(looks at the beaker perpendicular to the direction of the beam they will NOT see it)

26. The Tyndall Effect In a Mechanical Mixture/heterogeneous:
The light will scatter as it passes through the mixture because all particles are not dissolved
(look perpendicular to direction of the beam and you WILL see it!)

27. List the various homogeneous and heterogeneous mixtures in your home.
Partner Activity
List the various homogeneous and heterogeneous mixtures in your home.
Homogeneous
Heterogeneous

28. Mini-Lab: Compare Milk, OJ and Soda - Pure or Mixture? Pg. 238-239
Are they solutions or mixtures?
Homogeneous or Heterogeneous?
Did the extra magnification change you mind?

29. Chapter Review Questions: Page. 250-251: 1, 2, 4, 6 & 8