1. Chemistry
The Science of Matter
Pages 4-9 in the text

2. Do Now
List at least 5 chemicals that you are familiar with from past experience.

3. Learning Objective
Understand composition and their impact on the properties of matter
Be able to classify chemical vs. physical changes

4. Chemistry
The science that investigates the structure and properties of matter
Matter: anything that takes up space and has mass
Mass: the measure of the amount of matter that an object contains
NOT Matter-
Heat
Light
Radio waves etc.

5. Matter continued
Structure: refers to what it is made of and of how it is organized
Properties: Describe the characteristics and behavior of matter including the changes it undergoes

6. Behavior of Matter Determined by BOTH The elements it contains
Arrangement of those elements

7. Example Salt vs. Water Sodium and Chloride Hydrogen and Oxygen
Contain different elements --- Have different properties!

8. Example Aspirin Vs Table Sugar
Both contain only Carbon, Hydrogen and Oxygen molecules --- same composition
Different Structures Cause Different Behaviors!

9. Example
Two Different Artificial Sweeteners Aspartame Saccharine Different Compositions Both have: C, H, O and N and are sweet Only Saccharine has Na+ and S Their arrangement must be a factor!

10. Identifying Properties
Many are easy to observe by simple tests
Use heat, magnets, electricity etc
Color
State: solid, liquid or gas at room temp and pressure
Soft or hard
Does it burn?
Does it dissolve in water?
These are from a macroscopic perspective
Things you can touch, taste, feel, smell and see

11. What is it made of? This question is harder to answer
Must take measurements
Must observe chemical changes
Macroscopic Observations
Submicroscopic perspective
To understand hidden structure influences behavior

12. Physical change vs. Chemical change
Doesn't change what the substance is.
A new substance is formed and energy is either given off or absorbed.
Can be reversed
Cannot be reversed with the substance changed back without extraordinary means, if at all.

13. Examples Physical Change Chemical Change
Paper cut into pieces, small pieces are still paper
Paper burned is no longer paper
Dissolve sugar in water
Make a cake with flour, water, sugar and other ingredients and bake them, it would take extraordinary means to separate the various ingredients out to their original form.

14. Physical Vs. Chemical Change Worksheet (10 minutes)
In pairs complete the given handout
You may use your notes
Be sure that you are prepared to share your answers with the class

15. Share Answers (3 min/group)
Each table shares their answers with the class.
Be sure to explain why you chose your answer.
ALL STUDENTS MUST RECORD THE CORRECT ANSWER ON THEIR HANDOUT!

16. Thanks for doing your best work!
Exit Ticket – Answer individually Write your name! Please number your index card 1-5
List 5 different properties of matter which can be used to identify a substance.
Define Chemical change
Define physical change
List 3 examples of a chemical change
List 3 examples of a physical change.
PLACE YOUR EXIT TICKET IN THE TRAY ON YOUR WAY OUT!
Thanks for doing your best work!

17. Chemical properties vs. Physical properties
Chemical Property
• Flammability: The ability to burn
• Ability to rust: Reacts with oxygen to produce rust
• Reactivity with vinegar: Reacts with vinegar to produce new substances
Physical Property
• Transparency: The property of letting light pass through something
• Boiling point: Temperature at which a substance goes from liquid to gas
• Melting point: Temperature at which a substance goes from solid to a liquid
• Brittleness: Tendency to crack or break
• Ductility: Ability to bend without breaking
• Elasticity: Ability to be stretched or compressed then return to original size
• Density: Mass per unit volume

18. Let’s look closely at Density
It is an important property of matter
It is used to identify substances
It is also used to separate mixtures
Definition of Density: the mass of a specific unit of volume
It is expressed in the following equation;
D= m/v or density = mass
volume

19. Density In solids it is usually expressed as;
grams per cubic meter
g/cm3
Kilograms per cubic meter
Kg/m3
In liquids it is usually expressed as;
grams per liter
g/L
grams per cubic centimeter

20. Example of Density Calculations
If a piece of rock has a mass of 14g and a volume of 5 cm3, what is the density?
Step 1: Write the given and ensure proper units
m =14 g V= 5 cm3
Step 2: Write the formula
D= m/v
Step 3: Substitute the given into the formula
D = 14g / 5 cm3
Step 4: solve
D=2.8 g/cm3

21. Your turn to work! Alone, Silently Read the first 2 pages (4 min)
Highlight or underline any concepts which we have already mentioned as important, in ppt.
Circle any new information
Use a sticky note to write out any questions you have

22. Now you try some problems!
Work with your partner to answer questions for practice exercise 1 and 3 (10 min)
You may use a calculator
Write out all steps
Label all units
Be prepared to put your answer on the board!

23. Review answers

24. Submicroscopic Level of Matter
Matter is made of Atoms
Atoms
So small they can not be seen with the most powerful light microscope
So small that if a period at the end of a sentence were made of Carbon atoms it would be made of 100 quintillion carbon atoms
(100, 000,000,000,000,000,000)
Counting them at 3 per second would take you a trillion years!
Scanning Tunneling Microscope (STM)
creates computer images which are a visible perspective showing atomic location

25. Scanning Tunneling Microscope (STM)
individual iron atoms on a silver substrate

26. Using Chemical Models Show types and numbers of atoms
Show arrangement of the atoms and space filled

27. Why Models? Submicroscopic structural representation
Explains observed behavior
Used to predict behavior not yet observed
Built on investigation and experimentation

28. Show Connections Between Atoms

29. Classifying Matter Substance: matter with constant composition
Element: Made of only one type of atom
Compound: 2 or more elements that are chemically combined
Mixture: Matter with variable composition
Heterogeneous Mixture: Made up of more than 1 phase
Homogeneous Mixture: also called solutions, made up of only 1 phase

30. Mixtures
A material that is made of 2 or more things which are not combined chemically
Each of the parts still keep their own identities
Made by blending, but NOT forming chemical bonds or chemical change!
Most everyday matter occurs as mixtures

31. Heterogeneous and Homogeneous Mixtures
A classification of matter based on composition
Homogeneous mixture: no clumping or grouping but rather a uniform dispersal of the material it is made of.
Ex. Air; made of N2, O2, CO2 and other gases
A liquid in which there is a solvent and a solute is called a solution
Heterogeneous mixture: it is easy to identify all if the different components

32. Heterogeneous mixture

33. Heterogeneous mixture

34. Colloids (look homogeneous but microscopically heterogenous)
Hair spray
Smoke
Cloud
Whipped cream
Shaving cream
Blood
Styrofoam
Gello

35. Dispersion (Heterogeneous)
Dust
Milk
Hand cream
Gravel
Granite
Sponge

36. Homogeneous Mixtures

37. Solutions (homogeneous)
Air (gas)
Martini (liquid)
Salt water (liquid)
Plastic (solid)

38. Substances Homogeneous materials that contain only 1 kind of matter
Have definite composition and properties
Substances which can not be broken down into a simpler substance is an ELEMENT.
Substances which can be broken down into a simpler substance is a COMPOUND.
They are made of 2 or more elements

39. Elements Made of only one kind of atom
Can not be made simplified by physical or chemical means
Can exist as atoms (carbon) or molecules (N2)

40. Compounds Consist of 2 or more DIFFERENT atoms bound together (H2O)
Can be broken down into smaller types of matter by chemical means only.
Have properties which are different than the elements they are made of
Always contain the same ratio of its components atoms ( ex 2 hydrogen's to 1 oxygen, in water)

41. Classify the Following
Ocean water-
Calcium-
Vitamin C-
Dry ice –
Copper-
Grain alcohol-
after shave lotion-
Hamburger-
Al foil –
Milk-
Salt-
Iron nail-

42. Answers Ocean water- solution Calcium- element
Vitamin C- Compound ( L-asorbic acid)
Dry ice – compound (CO2)
Copper- element
Grain alcohol- compound (C2H5OH)
after shave lotion- heterogenous mixture
Hamburger- hetero
Al foil – element
Milk- solution
Salt- cmpd
Iron nail- element

43. Learning Objectives Investigate various ways to separate mixtures
Identify the properties of the matter that allow for a particular method of separation

44. REMEMBER Mixtures
Are made of 2 or more things which are not combined chemically
Each of the parts still keep their own identities
Made by blending, but NOT forming chemical bonds or chemical change!
Most everyday matter occurs as mixtures

45. Separating Mixtures
Mixtures can be separated through a physical process, (the identity of the substance remains unchanged).
Using their Physical properties
Bringing about physical changes to separate the mixture into its components (different substances it is made of)

46. REMEMBER: Physical Properties
Density: Mass per unit volume
Solubility in water : Does it dissolve in water?
State of mater: at room temp and pressure
Transparency: lets light pass through
Boiling point: Temperature at which a substance goes from liquid to gas
Melting point: Temperature at which a substance goes from solid to a liquid
Brittleness: Tendency to crack or break
Ductility: Ability to bend without breaking
Elasticity: Ability to be stretched or compressed then return to original size

47. Making a Mixture
AND
SAND SUGAR

48. The Mixture

49. How can we separate it? What do you think?
Work with your lab partner to come up with a suggested method. (10 minutes)
You may use your class notes, but your brain is your best asset.
Write your thoughts in your notebooks.
Do not be afraid to try!

50. Report out on ideas So, what did you come up with?
Share your thoughts! (10 minutes)

51. What can we do?
Method #1
Use a pair of tweezers and a microscope to physically separate the particles
Requires a lot of time and patience

52. Method #2 Step #1 Recall the properties of water and of sand
Sugar dissolves in water
Sand does NOT
Use the difference!
Method #2

53. Step #2 Recall the properties again
sand will not pass through a filter
Sugar and water solution will
Use the difference!

54. Step #3 Recall the properties of sugar and water water will !
sugar will not evaporate (change state) at 100 degrees Celsius
water will !
Use the difference!
Step #4

55. You have the two pure substances again!
Sand in the filter!
Sugar in the bottom of the beaker!

56. Learning objective
Understand the relationship between chemical change and energy change

57. Mixtures vs. Pure substances
Mixtures can be separated based physical properties and through physical change
Pure substances can only be separated through chemical changes
Separated from compounds into elements
H2O- H and O2
Made into compounds from elements
H + O  H2O

58. Chemical Change and Energy
All chemical changes involve some sort of energy change!
Many chemical changes (reactions) release energy
Exothermic reactions: release energy as heat
Some reactions absorb energy
Endothermic reactions: absorb heat energy

59. Epsom salt and laundry detergent
Demo
Epsom salt and laundry detergent

60. Lab Thursday! Paper Chromatography!
A method of separating mixtures based on their ability to dissolve or on the size of particles.

61. More methods of separating mixtures
Paper chromatography
Separating the dyes in ink
Dyes are usually made of several basic colors called pigments
Using the property of these dyes
Soluble in water we will separate the pigments

62. Develop a question! Make a claim (hypothesis) Follow the Procedure
Answer the lab analysis questions
Draw a conclusion
Ask a new question
Create a poster presentation of your results

63. Be sure to study your notes and your review sheets!
Unit Test on Monday!
Be sure to study your notes and your review sheets!