Confused about quantum principles

[rama1001]

Can anyone guide me ragarding the difference between excitation, de-excitation and ionization. I just confused with the terms de-excitation and ionization, wether they are same..please guide me..

 

[espen180]

Excitation and de-excitation refers to energy levels. an excited state is a state with more energy than the ground state, which is the lowest energy level. Excitation means the system is moving to a higher energy level, while de-exitation means that the system is moving to a lower energy level.

Ionization is a term unique to atoms, as far as I know, and refers to an electron being completely removed from its previously neutral host atom (or getting excited beyond the inifite-th energy state and into the continuum, if you want). It can also be used about a neutral atom picking up an electron.

 

[jambaugh]

With regard to an atom, excitation is an increase in the (quantized) energy of an orbiting electron (typically via collision or absorption of a photon). It may then undergo de-excitation (emitting a photon, or via collision giving up that energy to kinetic energy of the whole atom or of another particle.)

In the extreme case an excitation may "kick" the orbiting electron beyond the "escape energy" so it is no longer bound to the atom. This is ionization, splitting the atom into a free electron and free ion.

 

[A. Neumaier]

Can anyone guide me ragarding the difference between excitation, de-excitation and ionization. I just confused with the terms de-excitation and ionization, wether they are same..please guide me..

In terms of the spectrum, excitation means raising the energy to a higher discrete level, de-excitation lowering it ti a lower discrete value, ionization means raising it into the continuous spectrum (which means the particle escapes the potential it is in), and capture the transition from the continuous spectrum to a discrete level. Typically, the potential is the effective potential of an atom or molecule without the particle in question.