GRR..Stupid chem lab question

No one in my chem lab knows the answer to this question, so I come to you Southperry.

What are the three strongest Fraunhofer lines in the reflection of sunlight, what are their wavelengths, and what elements cause them?

Whoever answers this gets a free cookie

Most of your question can be answered here: http://en.wikipedia.org/wiki/Fraunhofer_lines

I would assume that "strength" refers to the amount of energy the wave has? There's an equation to find energy from just the wavelength, but I can't recall it of the top of my head. Wavelength is inversely proportional to energy so the shortest wave is the "strongest".

Heh, you silly chemistry people need more physics

Most of your question can be answered here: http://en.wikipedia.org/wiki/Fraunhofer_lines

I would assume that "strength" refers to the amount of energy the wave has? There's an equation to find energy from just the wavelength, but I can't recall it of the top of my head. Wavelength is inversely proportional to energy so the shortest wave is the "strongest".

Heh, you silly chemistry people need more physics

Yeah I was thinking this but wasn't sure. The question didn't really specify what "strongest" exactly meant. Thank you, though! cookie for you

Yay *omnomnom*

In the context of an observed spectrum, "strongest" usually means thickest or most obvious lines. What the question is asking is where you can find the three most OBVIOUS, or characteristic, spectrum lines, what their wavelengths are, and what elements cause them (references/google is your friend).

In the context of an observed spectrum, "strongest" usually means thickest or most obvious lines. What the question is asking is where you can find the three most OBVIOUS, or characteristic, spectrum lines, what their wavelengths are, and what elements cause them (references/google is your friend).

Probably googled this question at least a dozen times, but it didn't help because no websites specified what "strongest" meant. Websites would say lines A-K are strongest, but that didn't tell me which three are the strongest out of those. So yes, it is my friend, but not a very good one.

Probably googled this question at least a dozen times, but it didn't help because no websites specified what "strongest" meant. Websites would say lines A-K are strongest, but that didn't tell me which three are the strongest out of those. So yes, it is my friend, but not a very good one.

Are you given a Fraunhofer spectrum to look at? If you are, then pick out the three thickest lines. If there's multiple thick lines just pick three.

If you're not given a spectrum, then here's what I would use based on my searches:
Visible Fraunhofer spectrum - http://en.wikipedia.org/w/index.php?titl...svg&page=1
From this I would say D, E, and F are the most intense lines. Or at least they appear in the regions with the most contrast.

Wavelength vs. Intensity ("strength") graph - http://en.wikipedia.org/w/index.php?titl...svg&page=1
D, E, and F again show the most intensity of the labeled peaks.
EDIT: turns out intensity refers to the intensity of the sunlight and not the actual line absorptions. If you're not given a spectrum of your own then I would just ignore this tidbit because you shouldn't be expected to know this without reference material.

From here I would use a reference chart for what elements produce what wavelength, as found here - http://en.wikipedia.org/wiki/Fraunhofer_lines
Note that several elements contribute to both the D and E lines.

Are you given a Fraunhofer spectrum to look at? If you are, then pick out the three thickest lines. If there's multiple thick lines just pick three.

If you're not given a spectrum, then here's what I would use based on my searches:
Visible Fraunhofer spectrum - http://en.wikipedia.org/w/index.php?titl...svg&page=1
From this I would say D, E, and F are the most intense lines. Or at least they appear in the regions with the most contrast.

Wavelength vs. Intensity ("strength") graph - http://en.wikipedia.org/w/index.php?titl...svg&page=1
D, E, and F again show the most intensity of the labeled peaks.
EDIT: turns out intensity refers to the intensity of the sunlight and not the actual line absorptions. If you're not given a spectrum of your own then I would just ignore this tidbit because you shouldn't be expected to know this without reference material.

From here I would use a reference chart for what elements produce what wavelength, as found here - http://en.wikipedia.org/wiki/Fraunhofer_lines
Note that several elements contribute to both the D and E lines.

Thanks! Loads of useful information. We weren't given a spectrum, just an fyi. We made our own spectrometers in lab and had to take it home to do some homework questions and one of the questions was to use the spectrometer to view a reflection of sunlight, and find the strongest fraunhofer lines. Dumb question, right? Oh well, the assignment is already turned in.