Understanding Excitation Energy in Atoms: Threshold Values and Potential States

For instance, in the case of ionization, the threshold energy needed for the electron to escape the atom is determined by the binding energy of the electron to the atom. As long as the incident energy is above this threshold, it can cause ionization regardless of its specific value. In summary, the energy levels of an atom are quantized and for electrons to be excited to a higher energy state, the energy of the incident "entity" (photon or electron) must match the specific energy levels. However, for ionization to occur, the incident energy only needs to be above a certain threshold value.
  • #1
Bennet
My physics textbook says roughly that:

Within an atom; when electrons are raised from the ground state to the energy levels that comprise their various atomic spectra, the potential energy carried by either a photon or an electron (or other) must exactly match these quantitative energy levels to excite the electrons into a raised potential state.

And if the energy of the incident "entity" does not match these critical values then nothing happens at all?

Yet it seems to be the case that to cause Ionisation of the same atom, the specific level of energy can be completely imprecise as long as it meets the requirements of being above a threshold value

Is this the case or have I got the wrong end of the stick?

Many thanks for any help provided. If stupid please be kind as never been on a forum before. Thanks.

(Detailed insight beyond high school level would be greatly appreciated if applicable.)
 
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  • #2
Bennet said:
Yet it seems to be the case that to cause Ionisation of the same atom, the specific level of energy can be completely imprecise as long as it meets the requirements of being above a threshold value
I moved your question to the quantum section where I think it will get attention from people who can help with the math. However, what you say here is essentially correct. The energy levels of bound states are quantized, but unbound states are not.
 
  • #3
thanks
 
  • #4
Bennet said:
an electron (or other) must exactly match these quantitative energy levels to excite the electrons into a raised potential state.
Photon energy doesn't have to be exactly equal to the energy difference with some excited state for something to happen inside an atom. In general, interaction between atom and EM field causes a disturbance in which different energy eigenfunctions are coupled. It's just that the probability for the atom to end up in a level whose energy difference is closest to the photon energy is higher than those to end up in any other levels.
 
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Related to Understanding Excitation Energy in Atoms: Threshold Values and Potential States

1. What is excitation energy in atoms?

Excitation energy in atoms is the energy required to move an electron from a lower energy state to a higher energy state. This can happen when an atom absorbs a photon of light or collides with another atom or particle.

2. What is the threshold value for excitation energy?

The threshold value for excitation energy varies depending on the specific atom or molecule in question. It is the minimum amount of energy needed to cause an electron to move to a higher energy state. This value is determined by the energy levels and arrangement of electrons within the atom.

3. How is excitation energy related to potential states in atoms?

Excitation energy is closely related to potential states in atoms because potential states refer to the different energy levels or orbitals that electrons can occupy within an atom. Excitation energy is the energy needed to move an electron from one potential state to another.

4. Can an atom have multiple excitation energies?

Yes, an atom can have multiple excitation energies. This is because there are multiple energy levels or potential states that electrons can occupy within an atom. Each transition from one energy level to another requires a different amount of excitation energy.

5. How is excitation energy important in fields such as chemistry and astronomy?

Excitation energy is important in chemistry because it plays a critical role in chemical reactions, such as the absorption and emission of light. In astronomy, excitation energy is important for understanding the behavior of atoms in stars and other celestial bodies, and for identifying elements in distant objects through their unique emission spectra.

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