3. Determine the number of shells and the number of valence electrons for:
CARBON
2nd Period = 2 shells
4th Group =
4 valence electrons
Valence Electrons- electrons in outermost shell
Core Electrons- electrons an atom has contained in its inner shells

4. Determine the number of shells and the number of valence electrons for:
Sodium
3rd Period = 3 shells
1st Group =
1 valence electron
10 core electrons

5. Determine the number of shells and the number of valence electrons for:
Helium is the exception in Group 8
Since it has just one shell, that shell can only fit 2 electrons instead of 8
It is in this group because all the elements have a full outer shell
Helium
1st Period = 1 shell
8th Group =
2 valence electrons

6. Name and draw the atomic diagram and determine the number of shells and the number of valence electrons:
Symbol
Name
Diagram
# of Shells
# of Valence Electrons Ne H Be K S

7. Name and draw the atomic diagram and determine the number of shells and the number of valence electrons:
Symbol
Name
Diagram
# of Shells
# of Valence Electrons Ne
NEON 2 8 H
HYDROGEN 1 Be
BERYLLIUM K
POTASSIUM 4 S
SULFUR 3 6