 Wrap up

 You already know what this is ;)  Metals lose electrons and nonmetals gain electrons when they form ions  The charge on the ion is the oxidation number  You use the oxidation number (or ion charge) to write formulas like we have been doing!

 Vanadium is a transition element with multiple oxidation numbers. Write the names of the following compounds containing vanadium: V 2 S 3, VF 4, V 2 (SO 4 ) 3, V 2 O 5

 Ionic and covalent compounds vary enough that their differences can be used to classify and separate them from one another o Ex. Separating water from salt by distillation  Definition: is the method of separating substances in a mixture by evaporation of a liquid and subsequent condensation of its vapor

 Molecules of a single element that differ in crystalline or molecular structure are called allotropes  Another way to think about it is that allotropes are different forms of the same element  The properties of allotropes are usually different even though they contain the same element  Phosphorus has 3 common allotropes: white, red, black  Carbon: diamond, graphite, fullerenes  For the test know the allotropes of phosphorus and carbon!

 Trade-Names-of-Chemicals.php Trade-Names-of-Chemicals.php  Notice salt, water, ammonia, rubbing alcohol, baking soda, etc