1. Ion Formation & Ionic Bonding

2. Ion Formation Atoms are most stable when their valence shell is full and their electron configuration is isoelectric of a noble gas. An ion is an atom that has gained or lost electrons to gain a stable octet. an atom that loses electrons, has a positive charge is called a cation. An atom that gains electrons, has a negative charge and is called an anion.

3. Ion Formation Equations Na + IE  Na + + e - o Na has 1 valence electron, so applying Ionization Energy, the electron is removed and, it achieves the same electron configuration as Ne. O + 2e -  O 2- + EA o O has 6 valence electrons, so by gaining 2 electrons, it achieves the same electron configuration as Ne. Electron affinity energy is released.

4. Try These… Give the ion formation equations for: a)Cl - b)Mg 2+ c)N 31

5. Ionic Bonding Occurs when atoms exchange electrons to satisfy their stable octets. The resulting cation(s) and anion(s) are attracted to each other by electrostatic forces and a compound is formed. Using Lewis diagrams, we can show the formation of ionic compounds. Eg. NaCl 

6. Learning Check 1. Use Lewis dot diagrams to illustrate the formation of: a)lithium iodide b)barium chloride c)potassium oxide d)calcium fluoride 2. Predict the formula of each compound: a)magnesium chloride b)sodium sulfide c)aluminum oxide d)barium chloride e)calcium fluoride f)sodium iodide g)potassium chloride

7. Binary Ionic Nomenclature Remember: A cation is named with its regular name o Eg. Magnesium is the “magnesium ion” An anion is named with the –ide suffix o Eg. Cl - is the “chloride ion” Writing Formulas: 1.Write the chemical symbols 2.Add the ion charge 3.Determine how many ions of each type are needed using the crossover method. **Remember: all compound must be zero

8. Practice Write the chemical formula for the following ionic compounds and name the compounds. 1.Magnesium and chlorine 2.Sodium and nitrogen 3.Calcium and sulphur 4.Aluminum and oxygen

9. Multivalent Ions

10. Polyatomic Ions