1. Shells and Valence Electrons
-Electrons can be found in shells around the nucleus

2. Shells and Valence Electrons
Electrons can be in one shell or another, but never in the space in between.
Each shell can only hold a maximum number of electrons

3. Shells and Valence Electrons
The maximum number of electrons can be determined by this formula: 2n2
“n” is called the quantum number, which can be considered the shell number.

4. Shells and Valence Electrons
The outermost shell is called the valence shell
Valence electrons are electrons in the outermost shell
All other electrons are known as core electrons
valence
shell
valence
electron

5. Shells and Valence Electrons
Group 1A = 1 va. e-
Group 2A = 2 va. e-
Group 3A = 3 va. e-
Group 4A = 4 va. e-
Group 5A = 5 va. e-
Group 6A = 6 va. e-
Group 7A = 7 va. e-
Group 8A = 8 va. e-
(except Helium - 2 va. e-)

6. Valence Electrons Practice
Beryllium
Fluorine
Carbon
Write down how many valence electrons each element has and explain how you know using the vocabulary words “valence electrons” and “valence shell”