Start to a new unit

Today in chemistry class, we started our new unit: Chemical Reactions. We learned about several new and old concepts . I didn't find the lesson too difficult. However, I do need to review a few old ideas. First, we talked about clues of chemical reactions, and how they are different from physical changes. Below is a picture of some chemical reaction changes.

http://chemistrysaanguyen.weebly.com/61-evidence-for-a-chemical-reaction.html

Next, we discussed chemical equations and reviewed how to balance them. We learned that we can only change coefficients and not subscripts. In the picture below, you can see that the equation is balanced. On the left (reactants) there are 4 hydrogens because the hydrogen coefficient of 2 multiplies with the 2 subscript below the hydrogen. There are also 2 oxygens on the left. On the right (products there are 4 hydrogens and 2 oxygens to balance the equation. 

http://www.mikeblaber.org/oldwine/chm1045/notes/Stoich/Equation/Stoich01.htm

Here are a couple links to practice chemical equations and nomenclature. 

Jefferson Lab Balancing Act

Chem Team Chemical Nomenclature