Emission and Absorption bands?

[HMS-776]

I have been wondering lately, as I am quite new to physics.

If an atom dropped from it's first energy level back to it's ground state, and emitted a photon. Could a photon of the same wavelength excite the atom back to it's first energy level?

What is the difference between emission and absorption bands?

Can an atom be excited using the same wavelengths as it's emission bands if they were in order?

 

[Bob S]

Hello HMS-

If you have been reading my answers to your previous threads you already know this, but...

I explained to you the sodium D lines, the 3P to 2P transitions (~5890 and 5895 Angstroms), and the fact that cool sodium atoms surrounding the discharge can absorb some emissions from a hotter sodium atom emitter in a sodium discharge lamp. I specifically mentioned the dark band easily seen in the center of each yellow band using a diffraction grating was the absorption band of the cooler gas. So the hot emission spectrum is much broader than the cool absorption spectrum. Thus the cool gas cannot absorb all the emitted photons from the hot gas.
Bob S

 

[charng]

Hello, and welcome to the world of physics! I'm glad to hear that you are interested in learning more about emission and absorption bands.

To answer your first question, yes, a photon of the same wavelength can indeed excite an atom back to its first energy level. This is known as stimulated emission, and it is one of the fundamental principles behind laser technology.

Now, let's talk about the difference between emission and absorption bands. Both of these terms refer to the behavior of atoms and molecules when they interact with light. Emission bands refer to the specific wavelengths of light that are emitted when an atom or molecule transitions from a higher energy state to a lower one. These wavelengths are unique to each element or molecule, and they are often used to identify and study different substances.

On the other hand, absorption bands refer to the specific wavelengths of light that are absorbed by an atom or molecule as it transitions from a lower energy state to a higher one. These wavelengths are also unique to each substance, and they can be used to identify and study the composition of different materials.

So, to summarize, emission and absorption bands are two sides of the same coin, representing the behavior of atoms and molecules as they interact with light.

As for your last question, yes, an atom can be excited using the same wavelengths as its emission bands, as long as the energy of the incoming photon matches the energy required for the transition to a higher energy state. This is known as resonance, and it is an important concept in spectroscopy and other areas of physics.

I hope this helps to clarify the concept of emission and absorption bands for you. Keep asking questions and exploring the world of physics – there's always more to learn!