Now let's look at the final quantum number. The final quantum number is known as the electron spin quantum number. And this guy is represented by also a lowercase M but with a subscript S S for spin. Now, every orbital can have a maximum of two electrons. And what the Pole Exclusion Principle tells us is it states that any two electrons in any given atom can never have the same four quantum numbers. Remember, just like any car in any given state can only have one license plate one unique license plate any unique electron in any given atom will only have four quantum numbers unique to that electron.