Spin quantum number (s)

Spin quantum number (s)
Quantum numbers to-4 was proposed by George Uhlenbeck, Samuel Goudsmit Otto Stern and Walter Gerlach in 1925. Spin quantum number apart from the influence of angular momentum. This means that the spin quantum number is not directly related to the other three quantum numbers. Spin quantum number is not a solution of the wave equation, but based on observations of Otto Stern and Walter Gerlach of the spectrum that is passed on the magnetic field, it turns out there are two separate spectra with the same density. The separation of the spectral lines of the magnetic field is possible because the electrons surrounding the nucleus during spinning on its axis in different directions. Based on this proposed a spin quantum numbers to mark the direction of rotation (spin) of electrons on its axis.
Spin Quantum Numbers express direction of electrons rotate about its axis as the electron revolves around the nucleus of an atom. So, there are only two possible directions of rotation of the electron, ie clockwise and counter-clockwise, then the probability of the electron is spinning clockwise and anti-clockwise ½ 1/2. To distinguish the direction of rotation is marked positive (+ ½) is expressed by upward arrows and negative (- ½) represented by downward arrows. It is therefore understandable that an orbital can be occupied only a maximum of two electrons.