Why does an electron only have 2 spin states?

The Pauli Exclusion Principle states that, in an atom or molecule, no two electrons can have the same four electronic quantum numbers. As an orbital can contain a maximum of only two electrons, the two electrons must have opposing spins.

Why do we rotate half integers?

Half-integer spin fermions are constrained by the Pauli exclusion principle whereas integer spin bosons are not. The electron is a fermion with electron spin 1/2. The quarks are also fermions with spin 1/2. The difference between the two is that fermions take up space, while bosons can pile on top of one another.

What is meant by half spin of electron?

The spin number describes how many symmetrical facets a particle has in one full rotation; a spin of 12 means that the particle must be rotated by two full turns (through 720°) before it has the same configuration as when it started.

Why Fermions have half integer spin What does it mean?

Irfan Nafi said: What half-integer spin means, as in what is it. Spin is a quantum number, and it takes half-integer or integer values. A fermion (half-integer spin particle) obeys the Pauli exclusion principle and so its total wavefunction has to be antisymmetric (it also obeys Fermi-Dirac statistics).

What is the physics of a spin-1-2 particle?

When the probabilities are calculated, the −1 is squared, (−1) 2 = 1, so the predicted physics is the same as in the starting position. Also, in a spin- 1 2 particle there are only two spin states and the amplitudes for both change by the same −1 factor, so the interference effects are identical, unlike the case for higher spins.

What is the spin number of a fermion?

All known fermions, the particles that constitute ordinary matter, have a spin of 1 2. The spin number describes how many symmetrical facets a particle has in one full rotation; a spin of 1 2 means that the particle must be fully rotated twice (through 720°) before it has the same configuration as when it started.

Can we measure the spin of a particle?

First, particles “spin” in a sense but, as we will see, it is not a simple matter of measuring a rate of rotation for that spin. Second, it would be an impossibly monumental task.

Can a spiral in space spin continuously without becoming tangled?

A single point in space can spin continuously without becoming tangled. Notice that after a 360° rotation, the spiral flips between clockwise and counterclockwise orientations. It returns to its original configuration after spinning a full 720°.