Table of Contents
- 1 Why do we get a continuous spectrum rather than a tungsten line spectrum when light from an incandescent lamp is viewed with a spectroscope?
- 2 Which has the greatest energy a photon of infrared light of visible light or of ultraviolet light?
- 3 How might ultraviolet light be emitted by a hydrogen atom?
- 4 What happens as photons of visible light are absorbed by dye molecules?
- 5 When ultraviolet light falls on certain dyes visible light is emitted why doesn’t this happen when infrared light falls on these dyes?
- 6 What can you do with UV induced fluorescence?
- 7 Why do you need to know the wavelength of UV light?
Why do we get a continuous spectrum rather than a tungsten line spectrum when light from an incandescent lamp is viewed with a spectroscope?
Why do we get a continuous spectrum rather than a tungsten line spectrum when light from an incandescent lamp is viewed with a spectroscope? They literally glow when exposed to the combined visible and ultraviolet light of the Sun.
How does the difference in energy between energy levels related to the energy of the photon that is emitted by a transition between those levels?
How does the difference in energy between energy levels relate to the energy of the photon that is emitted by a transition between those levels? The energy of the photon is equal to the difference in energy between the energy levels.
Which has the greatest energy a photon of infrared light of visible light or of ultraviolet light?
Ultraviolet light photons have the greatest energy here, since the frequency of UV light is the highest.
Have you ever watched a fire and noticed that the burning of various materials often produces flames of different colors Why is this so?
Have you ever watched a fire and noticed that the burning of various materials often produces flames of different colors? The energy levels are different for the atoms and molecules of different materials—hence the different frequencies of radiation emitted when excitation occurs.
How might ultraviolet light be emitted by a hydrogen atom?
When an atom’s electrons move to a lower energy state, the atom releases energy in the form of a photon. When a hydrogen atom’s electron returns to the ground state, the light emitted is in the ultraviolet range of the electromagnetic spectrum.
Why does the hydrogen spectrum contain many lines even though the hydrogen atom has only a single electron?
Though a hydrogen atom has only one electron, it contains a large number of shells, so when this single electron jumps from one shell to another, a photon is emitted, and the energy difference of the shells causes different wavelengths to be released… hence, mono-electronic hydrogen has many spectral lines.
What happens as photons of visible light are absorbed by dye molecules?
Which of the following best explains what happens as photons of visible light are absorbed by dye molecules? Certain electrons in the dye molecule move to a higher energy level, with the difference in energy between the lower and higher energy levels being the same as the energy of the absorbed photons.
How do the frequencies of infrared visible and ultraviolet light compare?
How do the frequencies of infrared, visible, and ultraviolet light compare? Infrared light has a lower frequency than visible light, and visible light has a lower frequency than ultraviolet light. In a vacuum there are no particles for the light to collide with so it travels faster than it would in the atmosphere.
When ultraviolet light falls on certain dyes visible light is emitted why doesn’t this happen when infrared light falls on these dyes?
energy of visible light. However, since the energy of infrared light is lower than that of visible light, after de-excitation, the dyes will not emit visible light.
Why is ultraviolet light more effective than infrared light?
Why is ultraviolet light, but not infrared light, effective in making certain materials fluoresce? The ultraviolet light photons have higher energy than visible light photons, whereas the infrared have lower energy. Thus, some of the ultraviolet energy can be reemitted as visible color.
What can you do with UV induced fluorescence?
This phenomenon is referred to as UV-induced visible fluorescence. Observation of this fluorescence can be used by conservators as a non-destructive analytical technique to aid in the examination of objects.
Why do fluorescent minerals glow under UV light?
They glow with an amazing array of vibrant colors – in sharp contrast to the color of the rocks under conditions of normal illumination. The ultraviolet light activates these minerals and causes them to temporarily emit visible light of various colors. This light emission is known as “fluorescence.”
Why do you need to know the wavelength of UV light?
When looking for any UV light, it is extremely important to know what wavelength (in nanometers, or nm) the light is emitting at. Why is the wavelength so important? Well, in short, to be useful, a UV light needs to induce fluorescence.