This is a informative, free website for basic chemistry help. It is very student friendly and gives the information in an easy to understand format. The link that is used it to assist with the periodic table. It explain periods and groups. The larger website also includes information on atoms, reactions, and biochemistry. It has been around for about 10 years, so hopefully it is not going anywhere.
"Solve a Mystery with Science": Students get a hands-on look at chemical reactions using a color test as they work to solve a hypothetical medical mystery in the Crime Scene Chemistry project. [Source: Science Buddies, http://www.sciencebuddies.org/blog/2015/09/solve-a-mystery-with-science.php?from=Pinterest] #sciencefair #scienceproject #sciencekit