1. Elements and Compounds

2. Pure substances Have only one type of particle
Same composition throughout

3. 2 groups:
Elements
Compounds

4. Elements Cannot be separated by physical or chemical means
92 elements (naturally occurring)
Classified by properties

5. Unique Characteristic Properties of Elements
Melting point, Boiling point
Density,
Conductivity (heat and electricity)
Reactivity, etc

6. Look @ Fig.3 p83 Can you tell the 3 elements apart using…
1. density?

8. What about …
2. Conductivity?
3. Reactivity?
4. Melting Point?

9. A Substance is identified by
A set of properties
not any one single property

10. Three groups of elements have shared properties:
Metals (most elements)
Nonmetals
Metalloids

11. Metals … Shiny Good conductors Malleable Ductile
Have high melting & boiling points

12. Examples of metals Found on the left side of the Periodic Table
Most are solids except for Hg

14. Nonmetals Dull Poor conductors Brittle, unmalleable, not ductile
Lower Melting and Boiling points, Densities.

16. Metalloids Only 7 of them
Show properties of both metals and nonmetals:
some shiny, some dull;
somewhat malleable, ductile, etc.
Semi-conductors

17. The Metalloids Boron Germanium Silicon Arsenic Antimony Tellerium
Polonium

19. Quiz Identify group(s) of elements that have following properties: metals, nonmetals or metalloids
Good conductors of electricity
Brittle and unmalleable

20. Shiny
Poor conductors of thermal energy

21. Compare Metals and Non Metals

22. Review
Do Review
What is a pure substance?

23. Assignment:
Use a Periodic Table pR12-13 to fill in this table in your notebook:
Fill in the first 20 elements then add the ff 15 more …
Atomic Number
Element Name
Chemical Symbol 1
Hydrogen H 2

24. Iron, Cobalt, Nickel, Copper, Zinc, Silver, Tin, Gold, Lead, Mercury, Iodine, Bromine, Lanthanum, Actinium, Uranuim

25. Symbols derived from Latin names of elements
English name of the element
Symbol
Latin name of the element
Copper
Gold
Iron
Lead
Mercury
Potassium
Silver
Sodium
Tin
Tungsten Cu Au Fe Pb Hg K Ag Na Sn W
Cuprum
Aurum
Ferrum
Plumbsum
Hydrargysum
Kalium
Argentum
Natrium
Stannum
Wolfarm

26. Metal/Nonmetal/Metalloid?
Mini-project
Create Flashcards of each element
Get a ring or
Ziploc bag or
Make a
booklet
Element
Chemical symbol
Atomic Number
State at R.T.
Metal/Nonmetal/Metalloid?

27. The 2nd type of pure substance
Section 4-2 Compounds
The 2nd type of pure substance

28. Two or more elements chemically combined
Atoms combine in specific ratios
They CAN be broken down by chemical means
(Water into hydrogen and oxygen)

29. Compounds to know
(out of nearly 4 million kinds)
Table salt, water, carbon dioxide, glucose, baking soda (FORMULAS?)

30. A Chemical Formula
Symbols used to identify elements present
Tells ratio of element atoms present
Is constant for a particular compound

31. Chemical Formulas:
H2O H2O2
2 : : 2
CO2 H2SO4
1 : : 1 : 4

32. Mass Ratio is constant 2g : 16g 18g 1g : 8g Ratio: 1:8
Hydrogen + Oxygen Water
2g : g 18g
1g : g
Ratio: 1:8

33. Mg + O MgO 12g : 8g Ratio- 3:2 CAN be broken down by chemical means
e.g.(Water into hydrogen and oxygen)

34. Properties: Each compound has its own unique set Physical Properties …
Chemical properties …
Different from the elements that formed it
e.g. O, H : colorless, odorless gases
H2O : liquid.
Na -metal, Cl -green gas, poisonous
Sodium chloride- salt, colorless,
essential for health.

35. Law of Conservation of Matter
Matter is neither created nor destroyed;
It only changes from one form to another

36. Compds are classified by:
Their pH – How acidic or basic they are
If Organic (Carbon-containing) or Inorganic
The role they play
- Proteins – enzymes, structural
- Carbohydrates
- Lipids – fats & oils
- Nucleic acids

37. For more info…
Visit this photogallery of the elements