So if our electron is found with a principal quantum number of one, that means it must be in subsshell l equals zero, because l equals one minus one gives you zero. Likewise, p represents a subshell of l equals 1d represents a subsshell of l equals two, f represents a subshell of l equals three, and so on. Now, every subshell has a certain shape. In other words, every subshell has an orbital that has a certain shape. And the shape of the orbitals in any subshell represents the most probable location of our electrons. So shapes are based on mathematical probabilities where our electrons are located.