1. Modern Periodic Table

2. Modern Periodic Table Arranged by increasing Atomic Number
Rows Called Periods
7 Periods
Higher Number = more available electron energy levels

3. Horizontal Rows Called Periods 1-72 3 4 5 6 7

4. Groups Vertical Columns Called Groups or “families”.
Elements in same Group have similar chemical properties
All have same # of valence electrons

5. 18 Groups (Vertical Columns)

6. Periodic Law
Pattern of repeating properties of elements in groups

7. Cl 17 Chlorine 35.453 4 pieces of information in any square
Atomic Number
Element
symbol
Element Name
Average
atomic Mass
in amu
4 pieces of information in any square

8. Classes of Elements Atomic Numbers 1-92 occur naturally
Atomic numbers 93 and higher do not occur naturally
Synthetic (man made)

9. 3 General Classes of Elements
1. Metals: Good conductors of heat & electricity
Majority of Elements
On left side bold staircase
Most are malleable (hammered w/out shattering) & ductile (drawn into wires)
Most are solid except mercury (liquid)

10. 3 General Classes of Elements
2. Nonmetals: poor conductors of heat & electricity
Properties opposite of metals
To the right of bold staircase
Many are gases; solid ones are brittle (break when hit)

11. 3. Metalloids: Properties fall in between metals & nonmetals
Found on bold staircase
Ability to conduct electricity varies with temperature
Only conduct electricity at high temps.
Called semiconductors; used in computer chips
Ex: Silicon

12. Nonmetals
Metals
Metalloids

13. Periodic Trends From left to right across a period:
Elements become less metallic & more nonmetallic