Is it possible to change the direction or speed of atomic or moleculer spin?

Answer 1

Yes. The magnetic effects of iron are basically the result of the tendency of these atoms to couple themselves together magnetically and align their atomic spins. An external magnetic field will change the direction if this spin for many of the constituent atoms. Nuclear magnetic resonance (NMR) is a phenomenon resulting from the spin of atomic nuclei and their change under external magnetic fields that has application in medical imaging, among others.