Use this applet to explore in which order the atomic shells are filled with electrons. We start with hydrogen (Z=1). You can change the charge, and with it the number of electrons, by dragging the slider at the bottom. Alternatively, you can also use your "up" and "down" arrows on your keyboard. Electrons are shown by arrows "up" and "down" according to their spin. Each row of the scheme corresponds to one value of the principal quantum number (1-7). The rows are interrupted - each compact segment of a row corresponds to one value of the orbital quantum number (marked by letters: s, p, d, f).
© W. Bauer, 1999