1. Chapter 12

2. Do Now
Use our mixture of salt, pepper, and iron, and marbles to come up with a definition for mixtures.

3. Mixtures
A mixture is a physical combination of materials that can be separated by physical means.
Elements and compounds are mixed together but are not bonded together. The different materials keep their own properties. Therefore, they can be separated if you know their different properties.

4. Our Mixture Page 358 Salt Pepper Iron Filings Marbles
Dissolves in water
Pepper
Does not dissolve in water. Floats on water.
Iron Filings
Attracted to magnets
Marbles
Large, and easy to pick up

5. DO NOW 1. Think of common everyday mixtures. List a few.
2. If you pour salt into water or sugar into water, and then stir it up, where does it go?
3. How is salt in water and the sugar in water different than the mixture we used in class?

6. When you stir sugar into water…
It breaks apart and dissolves and spreads out throughout the water.

7. Solutions
A solution is a special mixture in which the substances are spread out evenly and will not settle.
Solute = the substance that dissolves
Solvent = the substance that does the dissolving

8. “You” climb in a “vent”
The solUte goes into the solVENT

9. In the sugar water solution, what is the SOLUTE?

10. In the Sugar water solution, what is the solvent?

11. How can you make a solute dissolve faster?
Stir or heat the solution or use smaller pieces.

12. Lots of things dissolve in water.
Therefore, WATER is called the Universal Solvent.

13. Types of Solutions 1. Solid in liquid 2. Liquid in liquid
EX: Salt water, sugar water
2. Liquid in liquid
EX: water and lemon juice
3. Gas in liquid
EX: carbon dioxide in water (seltzer)

14. Solubility
Solubility describes the amount of a substance that will dissolve in a particular solvent at a given temperature.

15. Solutions can be described as:
1. Saturated
Contains all the solute that can be dissolved. If you add more solute, it won’t dissolve.
2. Concentrated
Contains so much solute that it is close to being saturated
3. Dilute.
Far from being saturated
Dilute - Concentrated    Saturated

16. How to “dilute” something

17. Remember:
All substances have properties that we can use to identify them. For example we can identify a person by their face, their voice, height, finger prints, DNA etc.. The more of these properties that we can identify, the better we know the person.

18. In a similar way, matter has properties - and there are many of them
In a similar way, matter has properties - and there are many of them. There are two basic types of properties that we can associate with matter. These properties are called Physical properties and Chemical properties:

19. Types of Properties of Matter
1. Physical Properties
Readily observable
Can be measured without changing the material
2. Chemical Properties
Only observable during a chemical reaction
Describe how a material changes into other materials

20. PHYSICAL PROPERTIES

21. Physical Property Examples
Color
odor
mass
Volume
texture
Hardness
Appearance
melting point
boiling point
density
solubility

22. Boiling Point The point at which a liquid becomes a gas.
If you add HEAT, the molecules have more energy and escape as a gas.

23. The opposite of boiling
Condensing. It’s the point at which a gas becomes a liquid.
Water vapor (gas) comes into contact with a surface (usually cool) and returns to its liquid form.

24. Melting Point The point at which a solid becomes a liquid.
When you add heat, the molecules speed up and spread out and change from their rigid solid position to a liquid.

25. The opposite of melting
Freezing  The point at which a liquid becomes a solid

26. Solubility Dissolving
Substances that dissolve in water are called water - SOLUBLE.

27. Solubility Not Dissolving
Substances that do NOT dissolve in water are called water INSOLUBLE.

28. CHEMICAL PROPERTIES

29. Chemical Property Examples
Combustibility
the ability to react with oxygen
sensitivity to light
acidity / basic
radioactivity
Reactivity with water

30. Combustibility
How easily a substance will light on fire.

31. Sensitivity to light

32. Radioactivity
Atoms become very unstable and a material becomes hazardous.

33. How are Chemical Properties useful?
See page 382
mixtures from one another
fossils from rock
metals from ores
elements from solutions
They can be used to separate:

34. How else are Chemical Properties Useful?
To identify substances
Ex: Acids and bases are 2 common types of substances that react with other materials.
Acids
substances like vinegar and lemon juice
Turn blue litmus paper red
Bases
substances like household cleaners
Turn red litmus paper blue

35. Object Properties vs Material Properties
A Bar of Gold –

36. Do Now Yesterday in our lab, we saw matter change in 2 different ways.
What is the difference between the way matter changes in these situations:
tearing paper in half vs. burning it?
Mixing together sugar, flour , and eggs, and other ingredients VS putting that whole mixture into the oven and baking it to make a cake.

37. Make 2 columns in your notebook
Title the first column “Physical Changes”
Title the second column “Chemical Changes”

38. Study Jams!

39. Changes in Matter 2. Chemical Change 1. Physical Change
Does NOT result in production of a new substance
2. Chemical Change
DOES result in production of a new substance.

40. Physical Change Matter does not lose its identify Chemical Changes
- Change into a completely different kind of matter with different properties

41. Evidence of a Physical Change
Change in
position,
size,
shape,
volume,
state of matter
warming or cooling by refrigeration or heater

42. Evidence of a Chemical Change
Atoms rearrange to form new kinds of matter
Change in color
Formation of gas
Formation of a solid
Bubbles (not from boiling)
Fizzing
Change in temperature without refrigeration or heater
New odor
Burning
cooking

43. Physical Changes Example: Chemical Changes Example:
Tear a piece of paper into tiny pieces.
Chemical Changes
Example:
Combine baking soda and vinegar

44. Name that Change. Lets Play…………….

45. Physical Changes If you melt an ice cube, it’s still H2O.
If you break a bottle, it’s still glass.
If you paint a piece of wood, it’s still wood.
EX: melting, freezing, condensing, breaking, crushing, cutting, bending