1. Matter

2. Properties of Matter Two classes of properties:
Physical
Chemical
Physical: observable without changing composition of substance
Chemical: only observed if a change in composition occurs

3. Properties of Matter cont…
Two types of physical properties:
Extensive
Intensive
Extensive: properties that depend on the amount of material is present
Intensive: depends on the identity of the substance only, not the amount present

5. Physical Changes
A change of matter from one form to another without changing the substance itself.
Examples: phase changes, mixtures
Heating Curves: Lab

6. Chemical Changes
Entirely new substances with different properties
A + B  C (reactants go to products)

7. An Unexpected Color Change
Release or Absorption of Energy
Formation of a Precipitate (solid)
Formation of a gas

8. Chemical or Physical Frying an egg Boiling Water
Sanding a wooden plank
Digesting food
Popping a balloon
Chemical
Physical

9. Properties and Changes Practice
Properties: identify each as chemical or physical
Silver tarnishes
Copper can be pounded into a bowl
Helium is unreactive
Barium melts at 725°C
Potassium metal reacts violently with water
Changes: identify each as chemical or physical
Water condensates
Electricity changes water into hydrogen and oxygen
Yeast cells in bread make carbon dioxide and ethanol from sugar
Wood burns
Copper wire turns green over time

10. ATOM
Atom – the smallest unit of an element that maintains the properties of that element.

11. Pure Substance
A sample of matter, either a single element or a single compound, that has definite chemical and physical properties
Figure 14, Page 22

12. Elements
A pure substance
All atoms of the same element have the same atomic number

13. Two or more different elements joined by chemical bonds.
Compounds
A pure substance
Two or more different elements joined by chemical bonds.

14. The smallest unit of a substance
Molecules
The smallest unit of a substance
Has physical and chemical properties of that substance.

15. All of the following are molecules, but are they compounds or elements?
Br2
H2O O2 O3
C12H22O12
Element
Compound
Element
Element
Compound

16. Mixtures A combination of two or more substances
Not chemically combined
Examples are air, ice tea, and even cake batter
Proportions can vary

17. Homogeneous Mixtures Uniform distribution
Same proportions of ingredients
Examples: Gasoline, air, and syrup

18. Heterogeneous Mixtures
Not uniformly distributed.
Different proportions.
Examples: Chocolate chip cookie dough, vegetable soup and granite.

19. Homogeneous and Heterogeneous Mixtures

21. Classification Practice Classify the following as either a pure substance or a mixture. If a pure substance, is it an element or a compound? If a mixture, homogeneous or heterogeneous?
Concrete
Hamburger
Sucrose (table sugar)
Copper
Diamond
Copper (II) oxide
Saltwater
Milk
Dry ice (solid CO2)
Vitamin C

22. States of Matter

23. There are Four States of Matter
Solid
Liquid
Gas

24. Solids Particles are very close together
Have orderly, fixed arrangements
Fixed volumes
Particles can only vibrate in position

25. Liquids More random than solids.
Particles are loosely held together, but can move past one another.
Liquids can flow into any shape.
Definite volume.

26. Attractive forces between liquid particles may result in:
Cohesion
Attraction for each other
Adhesion
Attraction to other materials
Capillary Action
Ability to “climb” due to cohesion and adhesion
Surface Tension
Force that act on the surface of a liquid and that tends to minimize the area of the surface

27. Gas Essentially independent particles.
Large space between particles little to no attraction between particles.
Gases can flow into any shape
No definite volume

28. Changing States Condensation Deposition Sublimation Evaporation
Melting
Freezing

29. Heating Curves
Show the temperature in a substance when that substance is being given more heat energy.

30. Since mixtures are just physically combined, they can be separated.
Separating Mixtures
Since mixtures are just physically combined, they can be separated.

31. Separating Mixtures
Filtering – separation through differences in particle size
Decanting –separating by pouring
Distillation –separate two liquids based on differences in boiling points
Evaporation – removing a liquid to leave a solid
Chromatography – Separates by using a mobile phase and a stationary phase