Ions Sketch Notes

Intro to Ions

Win Some, Lose Some
ELECTRONS

Octet Rule

Atoms want stability! A stable atom has a full outer shell of electrons!

Our magic number for most elements is 8 valence electrons!

Exceptions:

●Helium has a full outer shell, with just two valence electrons

●Some larger atoms can have 9, but we will focus on 8

Noble Gasses already have a full outer shell!!

Most all other atoms need to form a bond to gain stability

Valence Electrons

Valence = Outer Shell Electrons

The Group Number can help identify the number of electrons in the outer shell

Group 1 = 1 valence electron

Group 2 = 2 valence electrons

Group 13 = 3 valence electrons

Group 14 = 4 valence electrons

Group 15 = 5 valence electrons

Group 16 =6 valence electrons

Group 17= 7 valence electrons

Group 18 = 8 valence electrons

Electron Dot Structures

1. Look at the Group #!

Group 13 (remove the one) and you have your three valence electrons

2. 1 dot = 1 valence electron

3. Singles before pairs!

What is an Ion

An ion is an atom with a charge!

Only way to change the charge of an atom is through gaining or losing electrons!

Neutral Atom: Protons = Electrons

Ion: Protons ≠ Electrons

Cations are pawsitive

Cations are metals who lost an electron!

Protons > Electrons = POSITIVE CHARGE

Groups 1-13 on the periodic table.

Sodium is in group 1 = 1 valence electron

Easier to lose 1 versus gain 7 for that full shell

Na → Na+

Anions are Negative

Nonmetals (Groups 15-17)

These will gain valence electrons

Protons < Electrons = NEGATIVE CHARGE

Chlorine has 7 valence electrons

Easier to gain 1 electron than to lose 7

Cl- Cl-