Mr. V. taught the class about polyatomic compounds today. Students must complete the worksheet on ionic compounds, from yesterday, and the sheet on polyatomic compounds from today. These are due tomorrow. Then Mr. V. demonstrated a variety of chemical reactions involving ionic and polyatomic compounds in solution. The production of a solid precipitate was evidence of the presence of certain ions (like group 17 ions and positive ions). The results of these demonstrations must be understood and used tomorrow in a lab.