Ionic bonding occurs when atoms of metals and non-metals combine to form ionic compounds. Atoms of metals will donate electrons to form cations, while atoms of non-metals will accept electrons to form anions. This transfer of electrons allows the atoms to achieve stable electron configurations similar to noble gases. Common examples are sodium chloride, which forms when sodium donates an electron to chlorine, and magnesium oxide, which forms when magnesium donates two electrons to oxygen. The chemical formulas of ionic compounds are written to balance the charges of the cation and anion.

1. Ionic Bonding

2. Why do atoms of different elements combine to form Ionic Compounds? Sodium Chlorine Sodium Chloride

3. Why do atoms of different elements combine to form Ionic Compounds? Human beings need to be complete in order for them to be happy. Ionic compound Consist of a metal and non-metal element Atoms of elements bond together in order for them to obtain a complete set of valence electrons in their outermost energy level. By obtaining eight valence electrons they become stable by satisfying the Octet Rule .

4. Charges and Number of Valence Electrons 1A 2A 3A 4A 5A 6A 7A 8A (1) (2) (3) (4) (5) (6) (7) (8)

6. - A system of representation wherein dots are used to show the number of valence electrons in atoms and molecules - Named after Gilbert Newton Lewis Lewis Dot Electron Structure

7. Lewis Electron Structure

8. The Ionic Bond Formation One atom of an element losing its electron to an atom of another element is known as the electron transfer. Ex. the metallic atom Na, gives one electron to a nonmetallic atom F. In the process, Na acquires a positive charge while F acquires a negative charge. Both achieves noble gas configuration. Oppositely charged ions are formed whenever a metal combines with a nonmetal.

9. Ionic Bonding Example…. MgO, magnesium loses two electrons to form a +2 cation, while oxygen adds two electrons to form a -2 anion.

10. Chemical Formula of Ionic Compounds Charges are used to predict the chemical formula of Ionic Compounds. The charge of a metal element and the charge of a non-metal element must be equal to zero when combined. If not trial and error is applied to come up with the sum which is zero. Metal elements are written before the non metal elements.

11. Writing Chemical Formula Aluminum, the more metallic element, is written first. Oxygen is written last since it is less metallic There are 3 atoms for oxygen, thus a subscript of 3 is written after the symbol while aluminum has 2. Aluminum Oxide Al 2 O 3

12. Writing Chemical Formula More examples: 1. Magnesium and Sulfur 2. Potassium and Nitrogen

13. Naming Simple Ionic Compounds Examples: Mg and O 2 MgO 2 Rule: 1. Name the metal (Mg is Magnesium) 2. Name the nonmetal ending in –ide (O 2 is Oxygen + -ide = ox ide ) 3. MgS is Magnesium oxide

14. Naming Simple Ionic Compounds KI - 2. CaBr 2 - 3. Al 2 O 3 - Potassium iodide 2. Calcium bromide 3. Aluminum oxide