1. Warm Up  Find the charges on the following ions: 6.Ca 7.As 8.Al 9.He 10.Mg 1.H 2.I 3.O 4.Kr 5.B 1+ 1- 2- 0 3+ 2+ 3- 3+ 0 2+

2. Density  Density is the ratio of an objects’ mass to its volume  Units: g/cm 3 or g/mL

3. Density  If a piece of gold has a density of 19.32 g/cm 3 and a volume of 10 cm 3, what is its mass?  D x V = M  19.32 g/cm 3 x 10 cm 3 = 193.2 g

4. Naming Binary Ionic Compounds  The name of a compound must distinguish it from other compounds made of the same elements.  Ionic compounds follow the pattern of:  Cation anion -ide  Cation: positively charged ion (the metal)  Anion: negatively charged ion (the nonmetal)  Atom: Iodine Ion: Iodide

5. Naming Binary Ionic Compounds  Name the following ionic compounds:  NaCl  Li 3 N Sodium chloride Lithium nitride

6. Writing Chemical Formulas for Ionic Compounds  Steps for writing the chemical formula for a binary ionic compound:  Write the cation (metal) first anion (nonmetal) second  Find the charge for each ion using the periodic table  “Criss-cross” the charges—write the charge of each ion as the number of atoms of the other element.

7. Writing Chemical Formulas for Ionic Compounds  Write the chemical formula for the following ionic compounds:  Sodium fluoride  NaF  Magnesium bromide  MgBr 2

8. Naming Covalent Compounds  The most metallic metal is first in the name  Most metallic=to the left on the periodic table  Prefixes tell the number of atoms of each element.  If there is only one atom of the first element, there is no prefix. CO = carbon monoxide not monocarbon monoxide

9. Naming Covalent Compounds Number of AtomsPrefix 1Mono- 2Di- 3Tri- 4Tetra- 5Penta- 6Hexa- 7Hepta- 8Octa- 9Nona- 10Deca-  Name the following compound: P2O5P2O5  Diphosphorous pentaoxide

10. Writing Chemical Formulas for Covalent Compounds  Write the chemical formula for the following compound:  Sulfur trioxide  SO 3

11. Law of Conservation of Matter  According to the law of conservation of matter, matter is neither created nor destroyed.  This means we must have the same number and type of atoms after the chemical change as were present before the chemical change. 2H 2 + 0 2 → 2H 2 0

12. Balancing Chemical Equations Cu + O 2 → Cu0  Step 1: take an inventory—write which elements and how many atoms of each are on each side  Step 2: Add coefficients to balance the equation ReactantsProducts ReactantsProducts Cu = 1 O = 2O = 1

13. Balancing Chemical Equations Cu + O 2 → CuO ReactantsProducts Cu = 2 O = 2  The coefficient multiplies all of the elements in the molecule by that number  2MgF 2 has 2 atoms of Mg and 4 atoms of F  Never change the subscripts (the little numbers beside the elements) 2Cu + O 2 → 2CuO

14. Types of Chemical Reactions  Synthesis  Decomposition  Single Replacement  Double Replacement

15. Worksheet Academic expectations: Review and learn density, naming ionic and covalent compounds, writing their formulas, and balancing equations in preparation for EOC May 9-10. Work alone or in groups. Complete by the end of class or finish for homework. Behavior expectations: Speak at volume that can only be heard at your table. Stay in your seat or ask for permission if you need to get up.

16. Closure  Class discussion:  Of the topics we went over today, which do you think will be the most important when you take chemistry in high school and/or college? Why?