Duduli

The polarizability of a hydrogen atom describes how easily it's electron cloud can be distorted by an external electric field.

When the external magnetic field becomes greater than the internal magnetic field (magnetic field due to orbital motion + magnetic field due to spin motion) then coupling between L(orbital angular momentum) and S(spin angular momentum) is broken down. In this case L & S preceses about external magnetic field B independently. This is called paschenback effect.

The splitting of energy level exhibited by atoms having zero spin is called normal zeeman effect.    Or The phenomenon of splitting of a spectral line into 3 components lines in presence of strong external magnetic field is called normal zeeman effect.

The states for which the probability density does not depend on time i.e independent of time is called as stationary state. i.e probability density(P) is                P=Ψ*(x)Ψ(x)

An electron moving around a nucleus of an atom is equivalent to magnetic dipole. When the atom is kept in an external magnetic field then electron orbit preceses about the external magnetic field direction. This precession is called larmors precession. I.e electronic orbit or angular momentum(L) of electron preceses about the external magnetic field. Larmors frequency,   f =eB/4πm  I.e larmors frequency is independent of angle between L and B. Where , B= external magnetic field              e= charge of electron              m= mass of electron

Answer:- According to Heisenberg's uncertainty principle “It is impossible to measure simultaneously both the position and momentum (or velocity) of a microscopic particle with absolute accuracy or certainty".