Do Now – March [3 + 3(7)], 2009 (Use your notes if you need to!) 1.What are three characteristics of ionic compounds? 2.What are three characteristics of covalent compounds?

Agenda Do Now/Announcements Compare and contrast ionic and covalent compounds Naming and writing formulas for covalent compounds Practice Time Exit Ticket

Objectives SWBAT compare and contrast ionic and covalent compounds. SWBAT name and write formulas for covalent compounds.

Molecule Spotlight N 2 O This is called dinitrogen monoxide. It is used as an anesthetic. It is also known as laughing gas.

Covalent Bonds in da House! Covalent compounds are EVERYWHERE! –Household cleaners (Ammonia) –Water! –Salad dressing –Political debate! (think greenhouse gases)

Essential Questions about Bonds 1.What kinds of elements come together in each type of bond? 2.What do the electrons do in each type of bond? 3.What state of matter are the compounds in at room temperature? 4.Low or high melting/boiling points? 5.Do they conduct electricity? 6.Do they dissolve in water?

Characteristics of Covalent Bonds (What you should know) 1. 2.Electrons are shared 3.Usually gases at room temperature 4.Low boiling and melting points 5.Most do not conduct electricity 6.Solubility depends on polarity

Ionic Bonds Covalent Bonds 1.Metal + Nonmetal 2.Transfer of electrons 3.Usually solids (r.t.) 4.High boiling and melting points (because of crystal lattice structure!) 5.Usually dissolve in water 6.Conduct electricity 1.Nonmetal + Nonmetal 2.Share electrons 3.Usually gases (r.t.) 4.Low boiling and melting points 5.Solubility depends on polarity 6.Usually do NOT conduct electricity

Can You Tell? With a partner, test your bonding skills to determine which compounds are IONIC and which compounds are COVALENT. You will then describe each type of bonds.

How to Name Covalent Molecules 1.Name the first element in the formula, using entire element name. 2.Name the second element, adding the suffix -ide. 3.Use prefixes to indicate the number of atoms of each type present in the molecule.

How to Name Covalent Compounds **Exception to prefix rule: DO NOT USE mono- when naming the first element. EXAMPLE: CO is carbon monoxide NOT monocarbon monoxide!!!

Prefixes Come BEFORE the Element Name # of AtomsPrefix# of AtomsPrefix 1mono-6hexa- 2di-7hepta- 3tri-8octa- 4tetra-9nona- 5penta-10deca-

Tricks of Naming If the prefix ends in “a” and is followed by “-oxide,” drop the “a” from the prefix Example: pentoxide NOT pentaoxide

Tricks of Naming Examples N 2 O 4 = dinitrogen tetroxide P 3 Cl 6 = triphosphorus hexachloride SO 3 = sulfur trioxide

Name the following molecular compounds… EXAMPLES CCl 4 As 2 O YOUR TURN TO NAME (in your table) SO NO 2 N 2 O P 2 O 5 PCl 5 ClF 3

Writing Formulas from Names 1.Look at the prefixes in front of each element to determine the subscript for each. 2.Write the first element first, second element second.

Writing Formulas from Names EXAMPLES Carbon tetrachloride Diarsenic trioxide Sulfur dioxide Nitrogen trifluoride YOUR TURN TO “FORMULIZE” (in your table) 1.Sulfure trioxide 2.Carbon monoxide 3.Carbon dioxide 4.Boron trifluoride 5.Tetraphosphorus hexasulfide 6.Xenon difluoride

Have you ever… Drunk a nice ice cold glass of dihydrogen monoxide?!?!? YES! You have! It’s just WATER!

Formulas and Names for Some Common Covalent Compounds (copy into notes) FormulaCommon NameTechnical Name H2OH2Owaterdihydrogen monoxide NH 3 ammonianitrogen trihydride N2ON2Onitrous oxide (laughing gas) dinitrogen monoxide O2O2 oxygendioxide

More Practice! Complete the worksheet on the back of the notes and leave it in the folder for Ms. Stroh to grade! If you do not finish, complete it for homework!

Exit Ticket 1.Name the following molecule… SO 3 2.Write the formula for… phosphorus pentabromide