Okay., today's our first class. So I'd like to begin with some important definitions. We're going to use these terms all semester. So pay close attention to begin with. Chemistry is basically this study of matter. Matter is everything that makes up the universe. In this class, we're going to study the various elements and how they interact with one another. Sometimes they unite. When two or more elements unite, we call them compounds. Now, uh, the study of chemical compounds is divided into two main branches of chemistry, organic chemistry and inorganic chemistry. Organic chemistry is the study of compounds that contain the element carbon. This basically covers well, uh, it covers all living things. Carbon is an element all living organisms have in common. As for inorganic chemistry, it's the study of non carbon based compounds. There are five differences between organic and inorganic compounds. Listen carefully to these. First, there are more than ten million carbon compounds. That's ten times the number of inorganic compounds. Why are there so many carbon compounds? Hm. Mostly because carbon bonds easily with other elements. It can also form complex cruise. Got it? Ok. Second, ah, organic compounds melt and boil at lower temperatures.