1. Ionic Bonding and Ionic Compounds

2. Atoms and Ions  Atoms are the building blocks of matter (solids, liquids and gases).  For example:  Copper wire is made of copper atoms.  Diamond is made of carbon atoms.  Oxygen gas is made of oxygen atoms.  Atoms have a negatively charged particle called electrons that spin around their nucleus.  Atoms are neutral because the protons equal the electrons.

3. How do Ions form?  Ions are atoms with charges (+ or -).  Some atoms have a tendency to either lose or gain electrons.  They do this to become stable, that is, to have a fully filled valence shell.  When atoms lose/gain e’s, they become ions.  When ions attract to each other, they form ionic compounds via a chemical bond known as ionic bonding.  Ionic compounds are neutral compounds.

4. Worksheet on Ion formation

5. Ionic Compound - Example

6. Example 1: Sodium ion  Sodium atom (11 e’s) has the electron configuration (2,8,1).  The 3 rd electron shell has a capacity for a maximum of 8 e’s.  However, in this case, there is only 1 valence electron.  Hence, sodium atom is unstable.  It is easier for sodium atom to lose 1 e than to gain another 7e’s  Thus, sodium atom loses that 1 e  It now has one less electron (but protons remain unchanged)

7. Example 2: Chloride ion  Chlorine atom (_____e’s) has the electron configuration (_______).  The 3 rd electron shell has a capacity for a maximum of 8 e’s.  However, in this case, there _________ valence electrons.  Hence, chlorine atom is _____________ as it is partially filled.  It is easier for chlorine atom to lose/gain _____ an electron than to lose/gain _____ e’s  Thus, chlorine atom loses/gains ____ e  It now has one _____ electron (but protons remain unchanged)

8. When ions attract….

9. Illustration using Electron Structure diagrams…

10. Ionic Bonding  Is a bond formed between positive and negative ions as a result of electrostatic attraction between them.  Electrostatic force is the attraction of positive and negative particles.  Positive ions are called cations.  Metals lose electrons to form cations.  Negative ions are called anions.  Non-metals gain electrons to form anions.

11. Ionic Bonding