1. Matter
Chapter 2

2. The Basics of Matter
Matter – is anything that has mass and takes up space – it is the “stuff” of which the universe is composed
Extensive properties – depend on the amount of matter in a sample
Mass, Volume
Energy, molarity (dilute or concentrated)
Intensive properties – depends on the type of matter in a sample, not the amount of matter
Density, freezing pt., boiling pt., absorbency, elasticity

3. The States of Matter State Definition Examples Solid
Rigid; has a fixed shape and volume
Ice cube, diamond, iron bar
Liquid
Has a definite volume but takes the shape of its container
Gasoline, water, alcohol, blood
Gas
Has no fixed volume or shape; takes the shape and volume of its container
Air, helium, oxygen

4. Physical Properties
Things you can tell about a substance just by looking at it
You don’t need to alter the composition of the substance to determine these
Examples:
Color - density
Odor - melting point
Volume - boiling point

5. mixtures and pure substances

6. PURE SUBSTANCES Always have the same composition
Pure substances are either elements or compounds
Examples:
Pure water (not lake/ocean water)
Copper
Zinc
rubbing alcohol

7. MIXTURES A substance with variable composition
Made up of multiple pure substances
Examples:
Air
Wood
Coffee
Cookie dough

8. Two Types of Mixtures
Homogeneous mixture – looks the same throughout – can’t see different parts
Ex: Kool-Aid, sugar cookie dough
Heterogeneous mixture – can see the different parts
Ex: chocolate chip cookie dough, sand and water solution

9. Practice
State whether each of the following is a pure substance, a homogeneous mixture, or a heterogeneous mixture.
Maple syrup
The oxygen and helium in a scuba tank
Oil and vinegar salad dressing
Common salt (sodium chloride – NaCl)

10. Practice
State whether each of the following is a pure substance, a homogeneous mixture, or a heterogeneous mixture.
Maple syrup
HOMOGENEOUS MIXTURE
The oxygen and helium in a scuba tank HOMOGENEOUS MIXTURE
Oil and vinegar salad dressing
HETEROGENEOUS MIXTURE
Common salt (sodium chloride – NaCl)
PURE SUBSTANCE

11. Separation of mixtures

12. Distillation
Boil the liquid off of a solution and leaves the other components behind
Laboratory display of distillation: 1: A heating device 2: Still pot 3: Still head 4: Thermometer/Boiling point temperature 5: Condenser 6: Cooling water in 7: Cooling water out 8: Distillate/receiving flask 9: Vacuum/gas inlet 10: Still receiver 11: Heat control 12: Stirrer speed control 13: Stirrer/heat plate 14: Heating (Oil/sand) bath 15: Stirring means e.g.(shown), anti-bumping granules or mechanical stirrer 16: Cooling bath.

13. Filtration Separates a liquid from the solid
The liquid passes through the filter paper, but the solid particles are trapped

14. Summary – Breaking Down Matter
HOMOGENEOUS
MIXTURES
HETEROGENEOUS
MIXTURES
Physical methods
PURE SUBSTANCES
ELEMENTS
COMPOUNDS
Chemical methods

15. Elements and Compounds

16. ELEMENTS
Fundamental substances that cannot be broken down into other substances by chemical means
Found on the Periodic Table of Elements (if it’s not on the chart, it’s not an element)
Examples:
Aluminum
Oxygen
Hydrogen

17. COMPOUNDS Compounds are combinations of different elements.
They can be broken down into their constituent elements by chemical changes.
A compound always has the same composition (i.e., the same combination of elements).
Examples:
Water (H2O)
Carbon Dioxide (CO2)

18. Element or Compound? Hydrogen peroxide (H2O2) Mercury (Hg)
Vanadium (V)
Sodium chloride (NaCl)

19. Element or Compound? Hydrogen peroxide (H2O2) Mercury (Hg)
Vanadium (V)
Sodium chloride (NaCl)

20. Chemical and Physical Properties

21. Physical Properties
Things you can tell about a substance just by looking at it
You don’t need to alter the composition of the substance to determine these
Examples:
Color - density
Odor - melting point
Volume - boiling point

22. Chemical Properties
These refer to the ability of a substance to form new substances (i.e., its reactivity)
Examples:
propane burns in the air
Baking soda fizzes if mixed with vinegar
A marshmallow gets black when toasted too long in a campfire
Hydrogen and oxygen react violently

23. Chemical or Physical? The boiling point of a certain alcohol is 78°C.
Diamond is very hard.
Sugar ferments to form alcohol.
Gallium metal melts in your hand.
Platinum does not react with oxygen at room temperature.
Your paper is white.

24. Chemical or Physical? The boiling point of a certain alcohol is 78°C.
Diamond is very hard.
Sugar ferments to form alcohol.
Gallium metal melts in your hand.
Platinum does not react with oxygen at room temperature.
Your paper is white.
Green is physical. White is chemical.

25. Chemical and physical changes

26. Physical Changes
Physical changes do not affect the composition of the substance.
Examples:
State changes (solid liquidgas)
Melting
Evaporating
Freezing
etc
Breaking a substance into smaller pieces

27. Chemical Changes
Chemical changes involve a change in the composition of the substance.
Examples:
Burning something
Reacting two substances to make something new
Running an electric current through water to decompose water into hydrogen and oxygen

28. Some practice… Chemical or Physical?
Iron metal is melted.
Iron combines with oxygen to form rust.
A piece of wood is burned in a fireplace.
A rock is broken into small pieces.
A log of wood is chopped up with an axe into smaller pieces of wood.
Water evaporates to become water vapor.

29. Some practice… Chemical or Physical?
Iron metal is melted.
Iron combines with oxygen to form rust.
A piece of wood is burned in a fireplace.
A rock is broken into small pieces.
A log of wood is chopped up with an axe into smaller pieces of wood.
Water evaporates to become water vapor.
Green is physical. White is chemical.

30. Recognizing a Chemical Change
Formation of a precipitate
A solid that forms and settles out of a liquid mixture
Change in color
Some reactions result in a change from one color to another
Production of a gas
Bubbles must be a new substance
Results of physical change are not new substances (ex: boiling)
Transfer of energy
Burning something gives off energy in the form of heat and light

31. Law of Conservation of Mass
“During any chemical reaction, the mass of the products is always equal to the mass of the reactants.”
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