What was the result? The likelihood of an electron being placed on a positive web page within an atom is proportional to the square of the orbital wave characteristic at that location. The electron cloud can be thought of in the following way: Imagine placing a square piece of paper on the floor with a dot in the circle representing the nucleus. An electron in this orbital is called an s electron. In atoms, an electrons location around the nucleus of an atom can be defined by four quantum numbers: the principal quantum number n , the orbital angular momentum quantum number l , the magnetic quantum number m l , and the electron spin quantum number m s.