1. Warm-up An ion is an atom that gained or lost electrons. Which of the following atoms is an ion: the left or right atom? What is the total charge of the ion? + + + + - - - - + + + + - -

2. Rules of Ions Rule 1: Opposite charges attract. “+” attracts “-” -+

3. Rules of Ions Rule 1: Opposite charges attract. “+” attracts “-” Rule 2: Charge = Protons - Electrons +4 protons - 4 electrons -------------- 0 charge +4 protons -3 electrons --------------- +1 charge +4 protons - 2 electrons --------------- +2 charge

4. Rules of Ions Rule 1: Opposite charges attract. “+” attracts “-” Rule 2: Charge = Protons – Electrons Rule 3: Valence electrons = Group # (1A to 8B) 1 2 3 4 5 6 7 8

5. Rules of Ions Rule 1: Opposite charges attract. “+” attracts “-” Rule 2: Charge = Protons – Electrons Rule 3: Valence electrons = Group # (1A to 8B) Rule 4: Atoms try to gain or lose electrons have a full outer shell. Lose electrons Gain electrons

6. Ionization + + + + - - - - +4 protons - 4 electrons -------------- 0 charge +4 protons -3 electrons --------------- +1 charge +4 protons - 2 electrons --------------- +2 charge The process of when an atom gains or loses electrons to become an ion.

7. Ionization + + + + - - +8 protons - 8 electrons -------------- 0 charge +8 protons -9 electrons --------------- -1 charge +8 protons - 10 electrons --------------- -2 charge The process of when an atom gains or loses electrons to become an ion. - - - - - - + + + + - -

8. Electronegativity How “greedy” an atom is for electrons. Strong electronegativity = greedy, steals electrons Weak electronegativity = not greedy, gives away electrons Give away electrons Steal electrons