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There are two primary mechanisms that broaden spectral emission (or absorption) lines: Doppler broadening and collision-induced broadening.
Doppler broadening occurs because of the relative thermal motions of the molecules in a gas. Simply put, the molecules are all bouncing off each other, so some are moving towards you and some away, some fast and some slow. Each molecule's spectrum is Doppler shifted by it's current velocity. The composite spectrum from all the individual molecules has its lines smeared out or broadened as a result. As you can guess, the amount of broadening depends on the temperature of the gas.
Collision-induced broadining, sometimes called pressure broadening, is is a result of the deformation of the molecules when they bounce off each other. For example, they may not be as symmetrical after a collision as they were before. These deformations perturb the quantum mechanical energy levels of the molecule, slightly shifting the frequencies of the emission or absorption lines. Just like Doppler broadening, the composite spectrum's lines are therefore broadened. This effect depends on both the pressure and temperature of the gas.
See spectralcalc for complete details and online simulations.
Starlight can be reddened by the Doppler Effect and by the gravity well (that light from a star finds itself in).
Wiki User
∙ 9y ago
Wiki User
∙ 8y agoWhat causes spectral lines is energy being emitted when "excited" electrons move from one energy level to another.
Wiki User
∙ 9y agoThe transition of an electron between two very specific energy levels causes each line of the emission spectrum.
Wiki User
∙ 13y agoA dark Line Spectrum is caused by atoms in the atmosphere of a star absorbing energy at the "dark line" frequencies.
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What is a line spectrum used for?
The line spectrum is usually used to sort out the atomic fingerprint as the gas emit light at very specific frequencies when exposed to the electromagnetic waves. The electromagnetic waves are usually displayed in form of the spectral lines.
Who created the hydrogen line emission spectrum?
Niels Bohr in 1913.
Why line spectrum is called finger print spectrum?
It is unique to a specific atom. The emission spectrum of sodium, for example, has two characteristic lines close together in the yellow part of the spectrum, which cannot be found in any other atom. Each line in a spectrum relates to a change in electron state or level.
The spectrum produced by glowing high-density gas is an a bright line emission b dark line absorption c chemical composition d temperature c continuous?
a Edit: The question is very mixed up, but I think I get the idea. It's obviously an emission spectrum. Because it is a high density gas the spectrum should be CONTINUOUS.
What causes an emission line 777NM?
light from flourescent light bulbs causes emission lines and the gas inside the bulb is cold leading straps of colors to come into appearance through a telescope. -chakshu
Is an atomic emission spectrum a continuous range of colors?
No. Atomic emission spectrum is non-contiuous and it is named as line spectrum.
The lines in the bright line spectrum of an atom are due to what?
The atomic line spectrum comes from the emission of atoms of different elements that are in an excited state. Each element has its own unique atomic emission spectrum.
What is a line spectrum used for?
The line spectrum is usually used to sort out the atomic fingerprint as the gas emit light at very specific frequencies when exposed to the electromagnetic waves. The electromagnetic waves are usually displayed in form of the spectral lines.
Which element did Bohr study the line emission spectrum of?
Niels Bohr studied the emission lines of Hydrogen.
Who created the hydrogen line emission spectrum?
Niels Bohr in 1913.
How can you Distinguish absorption spectrum from emission spectrum?
Emission spectra are bright-line spectra, absorption spectra are dark-line spectra. That is: an emission spectrum is a series of bright lines on a dark background. An absorption spectrum is a series of dark lines on a normal spectrum (rainbow) background.
What does the term bright line spectrum mean?
There are several kinds of spectra. Bright line spectrum, or emission spectrum, is when light emitted by a gas has an electrical discharge going through it, and it produces a spectrum of just a few isolated parallel lines.
If we would see a fifth line in the Balmer series emission spectrum. Calculate the wavelength associated with the fifth line?
m lmn ?,
Why line spectrum is called finger print spectrum?
It is unique to a specific atom. The emission spectrum of sodium, for example, has two characteristic lines close together in the yellow part of the spectrum, which cannot be found in any other atom. Each line in a spectrum relates to a change in electron state or level.
The spectrum produced by glowing high-density gas is an a bright line emission b dark line absorption c chemical composition d temperature c continuous?
a Edit: The question is very mixed up, but I think I get the idea. It's obviously an emission spectrum. Because it is a high density gas the spectrum should be CONTINUOUS.
How can emission spectra used to identify presence of specific elements in a substance?
In atomic spectroscopy, each element has a unique spectrum. The atomic spectrum obtained from a sample is a combination of the spectra of each elemental component. We take the strongest line from the sample spectrum and determine which elements could have caused it (we call these "candidates"). We then look at the full spectrum from each candidate and see whether or not every major line is present in the sample spectrum. If so, we say that element is present.Then we subtract the spectrum (or spectra) of the element(s) we have determined to be present from the sample spectrum and repeat the same process with the next strongest line in the (leftover) sample spectrum. We continue repeating this process until all lines in the sample spectrum are accounted for.
Where did Rubidium gets its name from?
The name rubidium refers to a red line in its emission spectrum that is similar to the color of rubies.
