Three things I learned about in this unit were that one, exothermic means that more energy was leaving the chemical reaction than it was taking in.  I also learned that endothermic reaction means that more energy was being taken in that given off.  The last thing I learned was that a chemical reaction happens when a new substance is formed.  What I liked best in this unit was the chemistry in a bag lab.  What I liked least in this unit was the test.  Here is my question; What is it called when a gas turns into a liquid?