There's a little bit of a probability involved, but this is actually the basis of how microwaves work, your microwave oven, is it causes the water molecules to get agitated in a rotational way, which increases the heat in that system.
Now we could also look at infrared light, which is once again, we have to remember, gets us into higher frequencies, and see what that does to molecules. So based on this simulation, it looks like the infrared light is when it gets absorbed, it causes this water molecule to start to vibrate. So microwave radiation caused it to rotate or to have a change in state of its rotation, while infrared makes it vibrate. And we could see that with other molecules as well.
Let's try carbon monoxide. Once again, it's not rotating it, it's causing it to vibrate. Now what about visible light? Well, visible light will have different interactions with different types of molecules, but let's try it out with nitrogen dioxide.
So there's certain situations where nitrogen dioxide will absorb, that's when you saw it glowing and what you see when it's glowing, what it's really doing is it's putting electrons into a higher energy state, or into a higher orbital and then when it stops glowing, it means that those electrons are going back to a lower energy state.
They are re-emitting radiation. So there, you can see it. You can see that just now, it's remitting visible light, in this case a different direction. And when it did that, the electron that was excited, went to a lower energy state. Now what about, let's think about ultraviolet light, which has even higher energy than visible light. What can that do? Well, here, we can see that it takes, in certain cases, electrons, and it's able to excite them so much that it's able to break that bond itself.
And so let me keep resetting it. So you can actually break bonds. Let's see what it can do to some ozone? A spectrum is a rainbow! This rainbow is created when a beam of white light is broken into its component colors, such as with a prism.
The colors formed are ordered according to their wavelength. When scientists look at this rainbow, they examine how intense the light is in each color. Is blue brighter than yellow, or is this specific red brighter than this other red? When material interacts with light, properties of that material are stamped on the light. This stamp is like a specific fingerprint for each element and molecule. By examining the intensity of light in each color, scientist can work backward to infer the properties of the material that touched the light along the way.
Spectroscopy is the study of the spectra produced when material interacts with or emits light. It is the key to revealing details that cannot be uncovered through a picture.
A spectrograph — sometimes called a spectroscope or spectrometer — breaks the light from a single material into its component colors the way a prism splits white light into a rainbow. It records this spectrum, which allows scientists to analyze the light and discover properties of the material interacting with it. Spectroscopy is as crucial as imaging to understanding the universe. Hubble is famous for the images captured by its cameras, but it often also relies on its spectrographs.
Continuous spectra arise from dense gases or solid objects which radiate their heat away through the production of light. Such objects emit light over a broad range of wavelengths, thus the apparent spectrum seems smooth and continuous. Stars emit light in a predominantly but not completely!
Other examples of such objects are incandescent light bulbs, electric cooking stove burners, flames, cooling fire embers and Yes, you, right this minute, are emitting a continuous spectrum -- but the light waves you're emitting are not visible -- they lie at infrared wavelengths i.
If you had infrared-sensitive eyes, you could see people by the continuous radiation they emit! Discrete spectra are the observable result of the physics of atoms.
There are two types of discrete spectra, emission bright line spectra and absorption dark line spectra. Let's try to understand where these two types of discrete spectra. Unlike a continuous spectrum source, which can have any energy it wants all you have to do is change the temperature , the electron clouds surrounding the nuclei of atoms can have only very specific energies dictated by quantum mechanics.
Each element on the periodic table has its own set of possible energy levels, and with few exceptions the levels are distinct and identifiable.
Atoms will also tend to settle to the lowest energy level in spectroscopist's lingo, this is called the g round state. In the diagram below, a hydrogen atom drops from the 2nd energy level to the 1st, giving off a wave of light with an energy equal to the difference of energy between levels 2 and 1. This energy corresponds to a specific color, or wavelength of light -- and thus we see a bright line at that exact wavelength!
An excited Hydrogen atom relaxes from level 2 to level 1, yielding a photon. This results in a bright emission line. Tiny changes of energy in an atom generate photons with small energies and long wavelengths, such as radio waves! Similarly, large changes of energy in an atom will mean that high-energy, short-wavelength photons UV, x-ray, gamma-rays are emitted.
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