1. Ions An atom with a positive or negative charge
An atom with a different number of electrons then protons
Gaining or losing electrons in order to increase stability (octet rule)
Octet rule- atoms can’t have more than eight valence electrons (most stable with 8 valence electrons)

2. Anion An atom gaining electrons and gaining a negative charge. Ex Cl-
Gains one electron and negative one charge
B3-
Gains three electrons and a negative three charge

3. Cation
An atom losing electrons and losing a negative charge to become positive. Ex
Mg2+
Loses two electrons and negative charge to become a positive two charge
Al3+
Loses three electrons and negative charge to become a positive three charge

4. Predicting ion Use octet rule
If less than 4 valence electrons losing electrons and negative charge to become positive
If more than 4 valence electrons gaining electrons and negative charge

5. Predicting Ions What Ion will Sodium form?
How many valence electrons does the element have?
1 valence electron
Is it going to lose or gain electrons?
Lose electrons
How many electrons does it lose or gain?
Lose 1 electron
What ion is formed?
Na1+

6. Predicting Ions What Ion will Oxygen form?
How many valence electrons does the element have?
6 valence electron
Is it going to lose or gain electrons?
Gain electrons
How many electrons does it lose or gain?
Gain 2 electron
What ion is formed?
O2-