Electric Dipole Transition: Selection Rules & n Transition

[neelakash]

I referred to hyperphysics to learn that for electric dipole transition,the selection rules are

$$\Delta$$$$\ l =$$$$\ 1$$

Or, $$\Delta$$$$\ l =$$$$\ -1$$

And, $$\Delta$$$$\ m_l =$$$$\ 0$$

Does not it include n transition?

How is n transition different from transition among the orbitals?

I mean n transition leads to different energy state...That I know.But does the transition among l lead also to different energy state?

 

[cadnr]

Selection rules in spectroscopy is not a fun area to study in my opinion, and to work out all the selection rules for a particular molecular system can be quite tiresome. Atoms are a lot easier than molecules, which is what I'm assuming you are referring to.

n is one of the simpler quantum numbers from a spectroscopic point of view. It refers to the electronic energy level, and can go up or down by any integer amount, or even stay the same during a transition. It is the "principle quantum number", or the quantum number of an atomic shell.

Transitions in l require a change in the orbital angular momentum of the electron in its shell, which happens every time a photon is absorbed. Higher l means more angular momentum for the electron and a higher energy in a given n shell. I can't remember much about m_l though, sorry! I think it's the projection of l on the atomic z axis.

 

[denian]

Thank you for bringing up this topic. The selection rules for electric dipole transitions are based on the conservation of angular momentum and parity. The change in angular momentum, represented by \Delta\ l, is indeed limited to 1 or -1. This means that the transition can only occur between orbitals that differ by one unit in their angular momentum quantum number (l). The change in the magnetic quantum number, represented by \Delta\ m_l, is limited to 0, which means that the transition can only occur within the same orbital (same l value). This selection rule is a result of the symmetry properties of the electric dipole moment operator.

Now, to address your question about n transition and how it differs from transition among orbitals - n transition refers to the change in the principal quantum number (n), which corresponds to the energy level of an electron. This type of transition can occur between any two orbitals, as long as the selection rules for angular momentum and parity are satisfied. However, the transition among orbitals, which is based on the change in angular momentum and magnetic quantum numbers, can only occur within or between orbitals with the same principal quantum number. This means that n transition can lead to a change in energy level, while transition among orbitals may not necessarily result in a change in energy level.

In summary, n transition and transition among orbitals are different in terms of the quantum numbers involved and the resulting energy changes. Both types of transitions are important in understanding the behavior of atoms and molecules, and they are governed by different selection rules. I hope this helps to clarify your confusion.