1. Matter – Properties and Changes

2. What is Matter? Matter is anything that takes up space and has mass.
Mass is the amount of matter in an object.

3. Types of Matter
Examples:

4. Properties Words that describe matter (adjectives)
Physical Property - a property that can be observed and measured without changing the substance.
Examples:
Chemical Property - a property that can only be observed by changing the type of substance.

5. Properties Words that describe matter (adjectives)
Extensive Property - depend on the amount of matter
Ex:
Intensive Property - only depend on the type of matter, not the amount
Used to identify a substance

6. States of matter
Solid- matter that can not flow and has definite volume.
Liquid- definite volume but takes the shape of its container (flows).
Gas- a substance without definite volume or shape and can flow.
Vapor- a substance that is currently a gas but normally is a liquid or solid at room temperature.

7. States of Matter Definite Volume? Definite Shape? Com-pressible? Solid
Expansion w/ Temp. increase
Com-pressible?
Small Expans.
Solid
YES
YES NO
Small Expans.
Liquid NO NO
YES
Large Expans.
Gas NO NO
YES

8. Condense
Freeze
Deposition
Melt
Boil
Solid
Liquid
Gas
Sublimation

9. States of Matter Plasma: Occurs at high temperature low pressure
Formed when electrons separate from nucleus of gases
Most common state of matter in the universe

10. Physical Changes & Chemical Changes
Changes in Matter
Physical Changes & Chemical Changes

11. Physical Changes
These alter the appearance of matter without changing its composition.
Examples?
Changes of the state (or phase) of matter is a physical change
The temperature & pressure at which matter changes phase are important physical properties
These are melting & boiling points

12. Another Way to Change States
Pressure
For some substances it will turn solids to liquids
EX: Ice Skating
For others it will turn liquids to solids
Ex: Silly Putty
Will turn gas to liquid
Compressor in refrigerator and AC
Will turn gas to solid
Formation of Dry Ice

13. Chemical Changes
Occur when one or more substances react and form a new substance
These are also called chemical reactions
Products of the chemical reactions ALWAYS have different properties than the original materials

14. Evidence of Chemical Reactions:
Formation of a gas
Formation of a solid
precipitate
Drastic color change
Energy changes – temp. changes or formation of light
Exothermic vs. Endothermic Reactions
Change in the smell of a substance

15. Conservation of Mass
Mass can not be created or destroyed in ordinary chemical changes
All the mass can be accounted for
Mass at the start = mass at end
So the total mass of the products should equal the total mass of the reactants

16. Antoine Lavoisier Considered the father of modern Chemistry
Discovered the Law of Conservation of Mass (also called the Law of Conservation of Matter)
Did experiments on reactions.

17. Mixtures A physical combination of two or more substances
Heterogeneous - you can see the individual substances that make it up.
Ex: Chocolate chip cookie dough, gravel, soil.
Homogeneous- you cannot see the individual substances that make it up, it always has a single phase.
Ex: Kool-aid, air.

18. Solutions Another name for homogeneous mixture
Can occur between any state of matter.
Examples:
Liquid
Solid
Gas

19. Separating mixtures Only physical changes - no new matter formed
Filtration- separate solids from liquids with a barrier
Distillation- separate because of different boiling points
Heat mixture
Catch purified vapor in cooled area

20. Chromatography- different substances are attracted to paper or gel, so move at different speeds
Crystallization – pure solids form when solid particles come out of solution (make crystals)

21. Elements & Compounds
Section 3.4

22. Elements Simplest pure substance
Cannot be broken down into simpler matter by normal physical or chemical means
All one kind of atom
Each one has a unique name and symbol. In the symbol the first letter is always capitalized and the remaining letter(s) are lowercase.
There are 91 naturally occurring elements
Who was given credit for organizing them into a table?
Dmitri Mendeleev

23. Compounds Chemical combinations of two or more different elements
When they are broken down, the pieces have completely different properties than the compound.
For example: Salt
Most of the substances we work with are compounds

24. Chemical Symbols Used to write chemical formulas
You know it is a formula because there will be more than one capital letter
Subscripts tell us how many of each atom in the formula.
H2O
C3H8
HBrO3

25. Laws of Compounds
By accounting for the mass of all matter there are a couple of laws that govern how compounds are created.
Law of Definite Proportions
Law of Multiple Proportions

26. Law of Definite Proportions
Each compound has a specific ratio of elements by mass
It is always a whole # ratio
For example – the chemical formula for water is always H2O
You can also see its ratio by mass:
Water is always 8 grams of oxygen for each gram of hydrogen
This does not change, no matter where you are on Earth! (Or in the universe for that matter)

27. Law of Def. Prop. Continued…
This law can be verified by determining the percent by mass of the elements in a compound:
Example: A compound contains g of iron and g of oxygen. What is the percent composition of oxygen?
30.05 % Oxygen

28. Law of Multiple Proportions
The textbook states that when the same elements combine to make different compounds, they combine in small whole number ratios.
You will NOT get fractions of elements
Examples:
CuCl vs. CuCl2
CH4 vs. C2H6

29. Review
What makes a form of matter a substance? What are some examples?
How do you distinguish between chemical and physical properties?
What is the difference between a physical change and a chemical change? Give one example of each.
Why is a solution a homogeneous mixture? What is one way to separate a homogeneous mixture?
Explain how you would tell that NaCl is a compound but Na is an element.
Explain how all compounds obey the laws of definite and multiple proportions.