2. #40 Octet, VE, and Lewis Dot Diagrams

3. *What does it mean to be reactive?
Some elements are only found in nature bonded with other elements; forming molecules.
Elements bond with other atoms because they are considered reactive.
What makes an element reactive?
An incomplete valence electron level due to not having full outermost shell.
Atoms bond with other atoms until a full level is complete.

4. Atoms that have gained or lost electrons are called ions.
*The Octet Rule
The “goal” of most atoms (except H, He, Li and Be) is to have an octet or group of 8 electrons in their valence energy level. (outermost shell)
They may accomplish this by either giving electrons away or taking them.
Metals generally give electrons,
nonmetals take them from other atoms.
Atoms that have gained or lost electrons are called ions.

5. *How to determine the number of Valence Electrons (VE)
Look at the group the element is located in to determine how many valence electrons an element gets
*Group 1 gets 1
*Group 2 gets 2
****Transition Metals (groups 3-12) only have 2 valence electrons****
*When looking at groups 13-18, just look at the number after the “1” and that’s the number of VE
Ex – group 13 gets 3

6. Examples of Group Elements with the same # of valence electrons
                          
How many electrons do each of these atoms have in their outer orbital/level? 87 Fr
(223) 55 Cs 37 Rb
85.468 19 K
39.098 11 Na
22.990 3 Li
6.941 1 H
1.008 + -
What group (family) do these elements reside in?

7. Lewis Structures Find out which group (column) your element is in.
This will tell you the number of valence electrons your element has.
You will only draw the valence electrons.

8. Groups - Review Group 8 = 8 electrons Group 1 = 1 electron
Except for He, it has 2 electrons
Group 2 = 2 electrons
Each column is called a “group”
3, 4, 5, 6, 7
Each element in a group has the same number of electrons in their outer orbital, also known as “shells”.
The electrons in the outer shell are called “valence electrons”

9. *Lewis dot diagrams
Lewis dot diagrams are visual representations of an atom by only using atomic symbol and valence electrons.
when drawing electrons always give each side one electron before giving it a second electron.
Example: sulfur Calcium

10. *Lewis dot diagram
Lewis dot diagrams are visual representations of an atom by only using atomic symbol and valence electrons.
-when drawing electrons always give each side one electron before giving it a second electron.
Example: sulfur Calcium Ca S

11. You try
Rubidium
Tin
Iron
Krypton
Silicon

12. Extra…

13. Lets practice… Calcium Bromine Aluminum Nitrogen Helium Potassium
Phosphorus
Germanium
Atomic symbol
Atomic mass
Atomic number
Protons
Neutrons
Electrons
Valence Electrons
Metal/ nonmetal/ metalloid
Group and period