Worst teacher i have had for chemistry and i've taken chem a few times before. If you don't have an extremely strong background, or you don't want to read the book 10 times and teach it to yourself, stay away from this guy. He doesn't teach and when he does, it doesn't make any sense. If you ask him for help, he treats you like you're a nuisance. He told me that if he couldn't teach me the material no professor could!