1. Ionic Compounds and Bonding
SNC2D – Academic Science

2. Learning Goals
Use Lewis dot diagrams to illustrate how a compound forms between a metal and a non-metal.

3. Ions are formed when electrons are gained or lost
Where do electrons that are lost go?
Where do the electrons that are gained come from?

4. Ionic Bonding
An ion is an atom that develops a charge after gaining or losing electrons.
Ionic bonding occurs between a metal and a non- metal element.
The metal ion loses its electron(s) and becomes positive!
Cation: a positively charged ion
The non-metal ion gains electron(s) and becomes negative!
Anion: a negatively charged ion

5. Ionic Bonding
The ions that are formed have a completed (full) outer energy level.
When the ions bond together, the overall charge of the compound is neutral.
Example
Sodium + Chlorine  Sodium chloride

6. Chemical Formulas
The chemical formula is a combination of symbols that represent a particular compound. It indicates which elements are present and the number of atoms of each element found in the compound.
Example
Calcium + Chlorine  Calcium chloride

7. Ionic Compounds
An ionic compound is a compound consisting of positive cations and negative anions that have resulted from the transfer of electrons from a metal to a non-metal.
The metal loses electrons and the non-metal gains electrons resulting in an overall charge of zero.
metal + non-metal  ionic compound

8. Ionic Compounds
Positive and negative ions are attracted to each other making the compound stable.
Ionic compounds are electrolytes, meaning that when dissolved in water, the ions separate and move freely to conduct electricity.