Junior high school science of atomic symbol that come out to the textbook, simple app that specializes in memorization of the chemical formula.
It can efficiently memorize and practice repeating the things you do not remember a simple test.
It can be switched between automatic mode and a manual mode, trying to memorize using effectively a bit of time.
Chemical symbol or chemical formula in the junior high school of science is learned in the second grade, and also to use even in the third year of the ion. Of course, it is also required to take.