ST. LOUIS -- When the Boston Red Sox signed Mike Napoli this past winter, there were a number of possible outcomes. He could hit a little, the way he had in 2012, putting up an OPS+ of 113. He could hit a lot, like he had in 2011, with a 173 OPS+ and 30 home runs. Most likely, he'd fall somewhere in between.
The fourth quantum number is the spin quantum number, s. There are only two values for s, +Â½ and -Â½. These are also referred to as 'spin up' and 'spin down'. This number is used to explain behavior of individual electrons as if they were spinning in a clockwise or counterclockwise.
These quantum numbers describe the size, shape, and orientation in space of the orbitals on an atom. The principal quantum number (n) describes the size of the orbital. Orbitals for which n = 2 are larger than those for which n = 1, for example.