1. SCH3U-4C Matter & Qualitative Analysis
Ions & Ionization
SCH3U-4C
Matter & Qualitative Analysis

2. Forming Ions
To satisfy the octet rule, certain elements have the tendency to gain or lose electrons from their valence shell
This results in a charged atom, or an ion.
We can represent the ionization of an atom using ionization equations.
Mg  Mg e-
F + 1 e-  F-
Cation (lost electrons, positively charged)
Anion (gained electrons, negatively charged)

3. Electron Configuration
Elements with a full outer shell of electrons are said to have a stable octet.
Neutral atoms will tend to gain or lose electrons to produce a stable octet, where the electron arrangement is the same as that of the closest noble gas.

4. Cations and Anions
Metals tend to lose electrons to form positive cations.
When representing cations using Lewis Diagrams, we show an ‘empty’ valence.
Non-metals tend to gain electrons to form negative anions.
When representing anions using Lewis Diagrams, a full valence is shown