Schlessinger Media has made an excellent introductory video explaining why a mere hundred or more elements produce the millions of different compounds and mixtures that make up our world. In Properties of Compounds, you will see that chemical bonds are the key to understanding how elements combine. The differences between ionic and covalent bonds are clearly presented. You will also see how valence electrons interact among atoms to form compounds, and learn how Lewis structures can help describe how easily an element will react. You will also explore the significance of the arrangement of the elements and are shown how to predict the behavior of an element from its position on the periodic table. I think you will the video very affirmative of what you learned last semester and a great introduction to the second semester. Enjoy!