1. Covalent Compounds

2. (c) McGraw Hill Ryerson 2007 share electrons Covalent molecules share electrons. two or more non- metals.  Covalent bonds occur between two or more non- metals.  These molecules exist as solids, liquids or gases.  Covalent molecules are like a play-pit full of plastic balls.  Each plastic ball = 1 covalent molecule of H 2 O Water, H 2 O See pages 184 - 185

4. (c) McGraw Hill Ryerson 2007 number of each elementThe chemical formula of a covalent compound tells us the number of each element in the compound. –Sometimes the names don’t tell us what elements make up the compounds. –Subscripts mean something different in covalent compounds smallest whole-number ratio between the ionsIonic compounds subscripts show the smallest whole-number ratio between the ions in the compound. actual number of atomsCovalent molecules have subscripts that show the actual number of atoms in the molecule. See page 193 Methane: CH 4 Hydrogen Peroxide: H 2 O 2 Water: H 2 O

5. (c) McGraw Hill Ryerson 2007 See page 193  What is the chemical formula for the molecule ethanol?  What is the name of the molecule C 12 O 22 H 11 ?  C 2 H 6 O, a name that must be memorized or looked up when needed.  Sucrose, also called table sugar.  What is the chemical formula for candle wax?  C 25 H 52

6. (c) McGraw Hill Ryerson 2007 2 non-metal atomsprefixes Covalent compounds with 2 non-metal atoms use a system of prefixes. See pages 194 - 195  Prefixes are often used before the atom name to indicate the number of atoms in the molecule.  Example:  CO = carbon monoxide  CO 2 = carbon dioxide  CCl 4 = carbon tetrachloride

7. (c) McGraw Hill Ryerson 2007 See pages 194 - 195  STEP 1: Write the most metallic atom (farthest left) first  STEP 2: Use prefixes to symbolize the # of each atom.  STEP 3: Add -ide to the end of the second atom’s name

8. (c) McGraw Hill Ryerson 2007 See pages 194 - 195  What is the chemical formula for the molecule trinitrogen tetrachloride?  What is the name of the molecule Si 3 P 6 ?  N 3 Cl 4  Trisilicon hexaphosphide

9. Covalent Compounds Write the names for the following covalent compounds: 1)P 4 S 5 __________________________________ 2)SeF 6 __________________________________ 3)Si 2 Br 6 __________________________________ 4)SCl 4 __________________________________ 5)B 2 Si __________________________________ 6)NF 3 __________________________________

10. Covalent Compounds Write the formulas for the following covalent compounds: 1)antimony tribromide __________________________________ 2)hexaboron silicide __________________________________ 3)chlorine dioxide __________________________________ 4)iodine pentafluoride __________________________________ 5)dinitrogen trioxide __________________________________ 6)phosphorus triiodide __________________________________