1. 3.2

2. And again.. (Start of 3.2) Atomic Number Atomic Mass
Number of protons & electrons in an atom
Atomic Mass
Number of protons and neutrons in the atom

3. Valence Electrons Remember energy levels? Valence Electrons
Electrons of different energy levels are found in different energy levels
Valence Electrons
Electrons at highest energy level
# of valence electrons helps determine chemical properties

4. Bell Work You need your textbook. Always.
Turn in Atomic Model Worksheet if you haven’t already
Get out Electron Dot Diagram paper
Quiz September 7th over atomic models (3.1) and 3.2 (Reading the periodic table, understanding what the numbers mean, distinguishing between a metal, nonmetal, metalloid, and why hydrogen is special). WRITE THIS IN YOUR AGENDA.

5. How many valence electrons? Most reactive in the periodic table.
Group 1: Alkali Metals
How many valence electrons?
Most reactive in the periodic table.
Why?
Lose 1 electron, left with 8, so stable.
Chemically stable or not?

6. Metals in General Pg 94; Represented in blue
React by losing their valence electrons
Reactivity depends how easily atoms lose valence electrons
Reactivity decreases as you go from left to right across periodic table
Why?

7. Alkali Metals Reacting to Water
Let’s talk about this first….
Li, Na, K
7pqOM

8. Group 2: Alkaline Earth Metals
What do you think makes these different from group 2?
Less reactive
2 valence electrons
Difficult to melt

9. Bell Ringer Again… You need your book. Always.
Quiz Friday over 3.1 & 3.2. LOOK OVER YOUR NOTES!!!!
Get out piece of paper and pencil.
Look at the element in group 14, period 7 (pg 688), and tell me….
Name
Atomic Number
Atomic Mass
# of P, N, E
# of valence electrons
Draw Electron Dot Diagram
Make sure your name is on it

10. Nonmetals Pg 94 Orange section
Become stable when they gain or share electrons
Can combine with nonmetals and metalloids by sharing electrons

11. React easily with other elements
Halogens
Group 17
React easily with other elements
Why?

12. Metalloids
Between metals and nonmetals
Scattered through Groups 13-17
Can lose or share electrons
Some properties of metals, some of nonmetals

13. Hydrogen Group 1 Metal or nonmetal?
Why?
Metal or nonmetal?
Nonmetal!
Properties different from alkali metals
Shares electrons
Stable at 2