1. Daily Science
Write the short hand configurations for the following elements:
Molybdenum and Ruthenium
Write the number of valence electrons Cobalt
Based on its group, how many valence electrons will Bromine have? Prove this.
Draw the electron dot diagram for Oxygen and Silicon

2. The Periodic Table
Pg.41

3. History
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4. Discovery Only knew 23 elements in 1790
Discovery of electricity brought change
Dmitri Mendeleev demonstrated a connection between atomic mass and elemental properties (1869)
Saw a repeating pattern
Left blank spaces where undiscovered elements should go (Sc, Ge, and Ga)
Henry Moseley rearranged the table according to atomic number
A clear repetition of physical and chemical patterns emerged. Called periodic law

5. The Modern Periodic Table
The columns on the periodic table are called groups (or families)
Elements in the same group have similar chemical and physical properties
The rows are called periods
Main group elements (representative elements): Groups 1-2, 13-18
Transition elements: Groups 3-12
Sometimes see a number/letter system
Can find elements based on group and period

6. Major groups There are 3 major groups on the periodic table: Metals
Nonmetals
Metalloids (or semiconductors)

7. Metal The metals are on the left side of the periodic table
Malleable and ductile
Shiny
Good conductors of heat and electricity
They further broken into 4 categories
Alkali metals
Alkaline Earth metals
Transition elements
Inner transition elements

8. Nonmetals Are on the right side of the stair-step (except H)
Can be gases
Brittle and dull
Poor conductors of heat and electricity
Br only nonmetal that is a liquid at room temp
Can be broken into smaller categories
Halogens
Noble gases
Carbon group

9. Metalloids Border the stair step line
Have properties of both metals and nonmetals
Si and Ge most important as they are used in computer chips