1. Periodic Table Of Elements

2. Groups Vertical columns
Elements of the same group have similar properties
Groups

3. Periods Horizontal rows Periods # 1 – 7
Each period begins with an element containing 1 electron in outer level and ends with an element with a full outer level of electrons

4. Electron Energy Levels
Electrons have different amounts of energy depending on where they are located in the electron cloud
Electrons in lower levels (closer to nucleus) have less energy than electrons in outer energy levels
Energy increases with each level

5. There are 7 energy levels
Each level has a number of sublevels equal to its energy level
Energy level 1 has 1 sublevel
Energy level 2 has 2 sublevels, etc
Each sublevel contains orbitals, one orbital can hold a max of 2 electrons

6. Sublevels
The first sublevel is s
Has one orbital
Holds 2 electrons

7. The second sublevel is p
Has 3 orbitals
Holds a total of 6 electrons
The Third sublevel is d
Has 5 orbitals, hold max 10 electrons
The fourth sublevel is f
Has 7 orbitals, hold a max of 14 electrons

9. Valence electrons Electrons in the outer energy level
All atoms can hold up to 8 electrons in their outer shell
H and He are the exceptions (they only have level 1s and therefore room for only 2 electrons max)

10. Group numbers tell the number of valence electrons for an element
Elements of the same group have the same # of valence electrons

11. Atoms want to have a full outer shell of valence electrons Atoms will share and exchange electrons in order to obtain a full outer shell This is chemical bonding

12. Elements of the same group number have the same number of valence electrons so they are likely to make the same types of bonds
This gives elements of the same group similar properties

13. The closer an atom is to having a full outer shell the more reactive it will be
Atoms can obtain a full outer shell by gaining electrons, losing electrons or sharing electrons with other atoms

14. Ions Atoms that lose or gain electrons Helps obtain a full outer shell
Atoms that lose electrons are (+) = cations
Atoms that gain electrons are (-) = anions

15. Electron dot diagrams Also call Lewis Structures
Uses dots to represent the valence electrons for an atom
One dot for each valence electron (group #)
Helps model bonding

16. Draw electron dot diagrams for the following elements:
Li, C, Kr, S and Ca
Which is the most reactive?
Which is the least reactive?

17. Quiz Please give the element symbol: Barium 7. Phosphorus
Mercury 8. Iron
Boron Xenon
Argon Flourine
Oxygen
Cadmium