Wow! I have used this site (prior to MERLOT membership) in class quite a bit...and on my own, as I was developing assignments or exams. It's handy and reliable. It's been accurate for every element I have used so far. The periodic table is really the best "cheat sheet" for any chemistry class. This one make the information behind the symbols very accessible to students. The instant access is such a plus, and the depth of knowledge adds to its reliability. I always caution my students on the use of web based information, and this was and is one site I have recommended to them.