1. Chemistry: Introduction to and Classification of Matter

2. Chemistry is…
The study of matter.

3. Matter takes up space has mass also known as having volume
the amount of matter something has

4. Things that are not matter…
Energy in the form of:
Light
Sound
Heat
- Shadows

5. Classifying Matter Pure Substance: contains only one type of matter.
Ex: pure water
Mixture: contains two or more types of matter.
Ex: pool water (contains water and chlorine)

6. Mixtures A mixture is a PHYSICAL blend of two or more substances.
Since they are only physically mixed, mixtures can be separated based on certain properties.
More on separating mixtures later…

7. A lesson in mixtures: Consider Primary Colors

8. Color Wheel

9. Back to chemistry…
Are all colors that exist MIXTURES of other colors?

10. Can you think of other things in your everyday life that are mixtures?

11. Examples of Common Mixtures
System
Example
Gas-Gas
Air
Liquid-Gas
Water vapor in air
Gas-Liquid
Soda, shaving cream
Liquid-Liquid
Vinegar
Solid-Liquid
Salt water
Solid-Solid
Sterling Silver

12. Classifying Mixtures Mixtures can be classified as HOMOGENEOUS
HETEROGENEOUS OR

13. Homogeneous Mixtures
a mixture in which the components of the mixture are uniform throughout.
Salt water and iced tea are good examples of homogeneous mixtures.
Also, the colors green, purple, etc. are mixtures.

14. Heterogeneous Mixtures
Heterogeneous mixtures do not have uniform composition.
A good example of a heterogeneous mixture is a salad.

15. Heterogeneous or Homogeneous?

16. Separating Mixtures
Separating mixtures can be done based on such properties as
1) boiling point,
2) magnetism,
3) solubility,etc.

17. Distillation
Distillation separates mixtures of liquids by boiling point.

18. Chromatography
Chromatography is based on different rates of migration of the components.

19. Filtration

20. Pure Substances
1. Elements: one type of atom that cannot be broken down by chemical means.
2. Compounds: two or more different types of atoms bonded together that can be broken down by chemical means.

21. Element or Compound?
element
element
compound

22. Atoms vs. Molecules
Atoms are the smallest particle of an element that retain the property of the element.
Molecules are formed when atoms are chemically bonded to one another.

23. Elements Can be either atoms or molecules.
All elements are located on the Periodic Table of Elements.
Examples of elements that are atoms:
Na, K, S, C, Au, Ag, Kr, etc.
Examples of elements that are molecules:
O2, H2, Cl2, N2
** Please note that both only contain one type of atom!

24. The elements that are molecules are called diatomic elements.
How am I supposed to know which elements are atoms and which are molecules??
That’s easy!
The elements that are molecules are called diatomic elements.
You need to memorize the words H O F Br I N Cl
Hydrogen (H2) Bromine (Br2)
Oxygen (O2) Iodine (I2)
Fluorine (F2) Nitrogen (N2)
Chlorine (Cl2)

25. The Periodic Table of Elements

26. Major Categories of Elements
1) metals 2) non-metals 3) metalloids
Metals are found to the left of the “staircase”
Non-metals are found to the right of “staircase”
Metalloids are found “on” the staircase

27. Properties of Metals Solid at room temperature (except Hg)
Shiny, Have luster
Malleable
Ductile
Generally have high melting points
Good conductor of heat and electricity
Have metallic bonds

28. Properties of Non-metals
Can be solid, liquid or gas at room temp
S  examples C, S, I2
L  Br2
G  O2, Ne, F2
Allotropes- different molecular forms of the same element (different properties, too) O2 and O3
Dull, lack luster
Brittle
Poor conductors

29. Compounds Compounds are formed when 2 or more different atoms join.
Compounds can be broken down into elements by chemical reactions called decomposition.
Common compounds to know:
NaCl sodium chloride (salt)
H2O water
NH3 ammonia
CH4 methane
CO2 carbon dioxide

30. Practice
Substance, element, atom

31. Practice
Mixture, compounds, molecules

32. Practice
Substance, elements, molecules

33. Practice
Mixture, elements, atoms

34. Practice
Mixture, elements, atoms and molecules

35. Practice
Substance, compound, molecules

36. Properties of Matter
Physical properties can be observed or measured with out changing the chemical composition (hardness, phase, color, volatility etc.)
Chemical properties are related to a substances ability to undergo chemical reactions.

37. Physical vs Chemical Properties
Physcial Properties (characteristics)
Chemical Properties (characteristics)
Mass
Corrosive
Volume
Flammable
Temperature
Combustable
Density
Oxidizer
Boiling Point
Reducer
Melting Point
Reacts
Hardness
Forms new products with …
Color
Stable
Phase (solid, Liquid Gas)
Unstable
Solubility
Anything that describes how it reacts

38. Reference Table - S Properties of Elements
Melting Point, Boiling Point and Density are all physical properties.
Examples:
What is the boiling point of helium in °C?
What volume would a 0.5 g sample of Oxygen occupy at STP?
In what phase would Calcium be found at 1000 K?

39. Solids Have definite shape Have definite volume Not compressible
Molecules are tightly packed
Can be amorphous (ex: silly putty, Play-Doh)
Symbol (s)

40. Liquids Have no definite shape; take the shape of its container
Have definite volume
Not very compressible
Molecules less tightly packed than in solids.
Symbol (l) means liquid
Symbol (aq) means “in a water solution” or a homogeneous mixture

41. Gases Have no definite shape; take the shape of its container
Have volume, not definite volume
Very compressible
Particles are less tightly packed than liquids
Symbol (g)

42. Phases of Matter

43. Physical vs. Chemical Changes
It is important to distinguish between changes in matter that are physical and those that are chemical.
PHYSICAL……….. or CHEMICAL???

44. Physical Changes
DO NOT change the chemical make-up of the sample of matter.
Ex: phase changes, change of color (without chemical change, like painting), grinding, tearing, etc.

45. Chemical Changes a NEW substance is produced.
Ex: rusting of iron, souring of milk, and combustion (burning).

46. How do we know that a chemical change has occurred?
Gas is produced
Chemical color change
Odor
Heat is produced
A precipitate (solid in a liquid) is formed.

47. Chemical vs Physical Change
Physical Changes
Chemical Changes
Boil
Reacts
Freeze
Forms new substances
Melt
Rusts
Condense
Decomposes
Dissolve
Spoils
Break
Combines with
Split
Burns
Crack
Combusts
Grind
Rots
Cut
Ferments
Crush
Explodes
Bend
Corrodes

48. Law of Conservation of Mass
Law of Conservation of Mass: Matter can be neither created nor destroyed; in every chemical reaction mass is conserved.

49. Practice
If 16 g of oxygen reacts with 2 g of hydrogen to produce water, how much water is produced?
18 g of water

50. WOW!