In groups discuss: How would you define a compound? Use some key vocabulary terms from the first chemistry test to help you. If H2O and H2O2 are both compounds, how are they different? How do atoms combine to form compounds? How do ionic bonds and covalent bonds differ? How are they the same? Think back to our global warming project. What compounds (greenhouse gases) have we already studied? Explain how the electrons move in order for each of the greenhouse gases to form. Label each greenhouse gas as an ionic or covalent bond.

Adapted from http://sciencespot.net/ Bonding Basics 8th Grade Science Adapted from http://sciencespot.net/

Section A: Complete the chart using a periodic table to help you.

NEGATIVE POSITIVE ION CATION ANION Answer these questions: An atom that gains one or more electrons will have a ____________________ charge. An atom that loses one or more electrons will have a ____________________ charge. An atom that gains or loses one or more electrons is called an ____________. A positive ion is called a ______________ and a negative ion is called an _______________. NEGATIVE POSITIVE ION CATION ANION “An-Eye-On” “Cat-Eye-On”

ELECTRONS COMPLETE METAL NONMETAL What is an ionic bond? Atoms will transfer one or more ________________ to another to form the bond. Each atom is left with a ________________ outer shell. An ionic bond forms between a ___________ ion with a positive charge and a ________________ ion with a negative charge. Example B1: Sodium + Chlorine Example B2: Magnesium + Iodine ELECTRONS COMPLETE METAL NONMETAL

Example B3: Potassium + Iodine Example B4: Sodium + Oxygen Example B5: Calcium + Chlorine Example B6: Aluminum + Chlorine

SHARE COMPLETE NONMETAL What is a covalent bond? Atoms ___________ one or more electrons with each other to form the bond. Each atom is left with a ________________ outer shell. A covalent bond forms between two _________________. Example C1: Hydrogen + Hydrogen Example C2: 2 Hydrogen + Oxygen SHARE COMPLETE NONMETAL

Example C3: Chlorine + Chlorine Example C4: Oxygen + Oxygen Example C5: Carbon + 2 Oxygen Example C6: Carbon + 4 Hydrogen

Bond With A Classmate Purple = Cations ; Pink = Anions Find a classmate to “bond” with and together decide on the correct chemical formula (use the oxidation numbers to help you!) You will have to decide how many of each ion you need to make a STABLE IONIC BOND. Record all bonds on your Date Book (data table) Look at the box on your paper for helpful hints You will have 5 minutes to make as many bonds as possible.

Review Vocab… What is an oxidation number? How is it determined? What is a subscript? What does it tell you about the atoms in the compound? What is a chemical formula?

Oxidation Numbers Same thing as typical charge an atom will have once it has lost or gained electrons Shortcut to writing chemical formulas: 1. Ca I 2. Ca+2 I1- 3. Ca+2 I1- Ca1 I2 CaI2

What about Magnesium and Oxygen?

Oxidation #’s Backwards Give me the oxidation state (charge) for each atom (polyatomic ion) in the compound for the following chemical formulas: Zn(OH)2 BeSO4 Mg3P2 MgBr2 KCl NH4OH

Naming Ionic Compounds Metal and nonmetal: Name the metal and change the nonmetal to –ide Transition metals and nonmetals: Use roman numerals to represent the charge and name the nonmetal using –ide Polyatomic Ions : If positive are more like metals and come first, if negative are more like nonmetals and come second. They have their own names and oxidation numbers (see chart on back)

Naming Ionic Bonds Practice What is the chemical formula for the compound that results when Magnesium and Chlorine combine? Use the lewis dot structures and the criss cross method to show how you get the same formula. How do you name this compound?

More Polyatomics...

Show me the formula Ammonium Chloride Potassium Nitrate Calcium hydroxide Sodium Oxide Copper (II) Sulfate

Name that Compound… NaCl NaCO3 NaOH NH4OH Fe2(SO4)3

Naming Covalent Compounds Guidelines for Inorganic Compounds 1 Mono- 2 Di- 3 Tri- 4 Tetra- 5 Penta- 6 Hexa- 7 Hepta- 8 Octa- 9 Nona- 10 Deca- In covalent compounds, the least electronegative element comes first and its name is unchanged. 2. The more electronegative element comes second and takes on the –ide ending like in ionic bonds Subscripts are represented by Greek prefixes Example: H2O –dihydrogen monoxide

Name that Compound Can you use the inorganic guidelines for all of these? 4. CH4

Show me the formula hexaboron silicide chlorine dioxide hydrogen iodide iodine pentafluoride dinitrogen monoxide