1. Section 4.1
Atoms and Ions

2. Ion:
an atom which has become charged by gaining or losing one or more electrons.

3. Trends in Periodic Table: Ability to Lose Electrons
Decreases as you move across a period

4. Trends in Periodic Table: Ability to Gain Electrons
Increases as you move across a period
Stronger nuclear charge as the number of orbits stays the same but number of protons increase.

5. Definitions
Cation:
An atom that loses electrons and becomes positively charged.
Anion:
An atom that gains electrons and becomes negatively charged.

9. Rules for Bohr-Rutherford IONS
1. Calculate p+ and n0 just as you did for neutral atoms.
2. When determining the number of electrons add or subtract according to the charge given.
If the charge is positive subtract, if it is negative add electrons!
Example: O -2 8

11. Summary of Ions:
Electrons lost or gained lie on the valence shell (outer most shell)
If there are less than 4 electrons in an atom’s valence shell it prefers to loose these electrons.
If there are more than 4 electrons in an atom’s valence shell it prefers to gain the remaining electrons to have a full octet.

12. What does Na look like?
What does Na 1+ look like?

13. Na and Na 1+

14. Fluorine: Bohr-Rutherford and Naming
Draw a Bohr-Rutherford Diagram of Fluorine
Draw its ion
Note: “-” ions get an “ide” ending

15. Draw the ionic form of first 20 elements ( Bohr Rutherford diagrams WS)+1 +2 +3
+/-4 -3 -2 -1