Ionic and Covalent Bonds Science 10 Ms. Lowrie

Using Lewis Diagrams to Show: Covalent Bonding Steps: 1. Draw a Lewis diagram for both elements 2. Determine how to fill valance shell of both by sharing electrons 3. Redraw Lewis diagrams together 4. Circle ‘shared’ electrons

Covalent Examples a) Hydrogen (H) and Chlorine (Cl) b) Water = Hydrogen (H) and Oxygen (O)

More Covalent Examples c) Carbon (C) and Hydrogen (H) d) Fluorine (F) and Fluorine (F) e) Phosphorus (P) and Chlorine (Cl) f) Carbon (C) and Chlorine (Cl)

Practice: Draw Covalent Bonds 1. Hydrogen and Hydrogen 2. Ammonia = Hydrogen and Nitrogen 3. Chlorine and Chlorine 4. Nitrogen and Fluorine 5. Oxygen and Chlorine 6. Hydrogen and Fluorine 7. Iodine and Iodine 8. Carbon and Fluorine

Using Lewis Diagrams to Show: Ionic Bonding Steps: 1. Draw a Lewis diagram for each element 2. Use arrows to show how the electrons move Example (a): Potassium (K) and chlorine (Cl)

More Ionic Examples b) Sodium (Na) and oxygen (O) c) Calcium (Ca) and chlorine (Cl) d) Barium (Ba) and fluorine (F) e) Aluminum (Al) and Oxygen (O)

Practice: Draw Ionic Bonds 1. Potassium and Phosphorus 2. Sodium and Fluorine 3. Aluminum and Chlorine 4. Potassium and Fluorine 5. Lithium and Oxygen 6. Calcium and Phosphorous 7. Sodium and Nitrogen 8. Aluminum and Bromine

Writing Chemical Formulas Crossover Method Shortcut to writing ionic compound formulas Steps: 1. Determine ions (write cation first) 2. “Crossover” - Write ion # as subscript (bottom #) for other element Notes: Do not write +1 Write -1 as - If charges are equal (+2 & -2) = 1 each

Crossover Method – Example a) Barium and Chlorine BaCl 2

More Crossover Examples b) Beryllium and Phosphorous

More Crossover Examples c) Potassium (K) and Phosphorous (P) d) Sodium (Na) and Fluorine (F) e) Aluminum (Al) and Oxygen (O) f) Potassium (K) and Fluorine (F)

Practice: Crossover Method 1. Lithium and Oxygen 2. Calcium and Phosphorous 3. Calcium and Chlorine 4. Aluminum and nitrogen 5. Beryllium and Oxygen 6. Beryllium and Nitrogen 7. Potassium and Sulphur 8. Sodium and Oxygen

Practice Worksheets 1. “Ionic vs. Covalent Bonds” Last 2 questions 2. “Write formulas for the following:” Using Crossover Method

Polyatomic Ions Ions made up of 2+ ions “poly” = many

Polyatomic Ion Formulas Notes on formula writing: Use brackets to keep polyatomic ion “together” Write cation first

Example a) Write formula for: NH 4 1+ and S Draw: 2. Use Crossover Method:

Examples & Practice b) Calcium & Nitrate c) Sodium & Hydroxide d) Sodium & Sulfate e) Calcium & Phosphate f) Lithium & Hydrogen carbonate

Practice Worksheets 1. “Polyatomic Ion Practice” 2. “Writing Formulas” No naming yet!

Naming Ionic Compounds Steps: 1. Write cation first 2. Write anion last with suffix (ending) “ide” Potassium Chloride Note: Do not include ‘numbers’!

Naming Ionic Compounds: Examples a) Ba and Cl b) Sodium and Fluorine c) Be and P d) Ca 2+ and Cl- e) Al 3+ and N 3- f) Na 2 O g) K 3 P

Naming Ionic Compounds: Practice 1. Be 2+ and O Be 2+ and N K+ and S Al 2 O 3 5. KF 6. Li 2 O 7. Ca 3 P 2 Polyatomic Ions: Same “ordering” rule! Don’t change to “ide” 1. Ca & NO 3 2. Na & OH 3. Na & SO 4 4. Ca & PO 4 5. Li & HCO 3

Naming Ionic Compounds: Practice 1. “Writing Formulas” worksheet With names now! Complete the following textbook questions: #9, 10 (on page 113) #2 (pg 115) #4 (on pg 117)

Naming Covalent Compounds Steps: 1. Add numerical prefix (beginning) to both elements Ignore ‘mono’ for 1 st element 2. Add “ide” suffix (ending) to second element Note: When prefix ending in O or A is added to oxide, drop last vowel of prefix

Naming Covalent Compounds: Examples a) N 2 S 4 dinitrogen tetrasulfide b) NI 3 nitrogen triiodide c) XeF 6 xenon hexafluoride d) CCl 4 carbon tetrachloride e) P 2 O 5 diphosphorus pentoxide f) SO 3 sulfur trioxide 1mono 2di 3tri 4tetra 5penta 6hexa 7hepta 8octa 9nona 10deca * Second element in ‘ide’ from * Drop –a & -o before ‘oxide’

Naming Covalent Compounds: Practice “Nomenclature – Covalent Compounds” worksheet Complete the following textbook questions: #9, 10 (on page 123)