Spectra Definition and 264 Threads

Where could I find the spectra of most elements on line? I would expecially the He 2 spectrum, the Be and the B ones. Where could I find it?

I was given 400 nm. I was tasked to find n but i kept getting a value which is a not a integer. The value of n must be an integer right? 1/W = R(1/4 - 1/n^2) manipulate n=sqrt(4RW/RW-4) where R=1.097e7 n=6.752 I am thinking to make n as 6. But are there values of n greater than 5?

Hi Guys! *waves* Anyway, I was just wondering what conditions and in what state are atoms sufficiently isolated so that it gives rise to a line spectra. I thank you all for any help you provide in advance. Many thanks, Icetray

[b]1. Explain the physical principles of the production of spectra by diffraction gratings. include production of zero, first and second order spectrum. Homework Equations The Attempt at a Solution Diffraction and interference?

I don't really have a HW question, I am doing physics independent study and I have to do a project. My teacher suggested doing it about emission spectra, only, I have no idea what that is and searching EBSCO is not being really helpful, does anyone have any resources, ideas, etc where I could...

Hi, I have found several links using google to emission spectra of the Earth: http://lasp.colorado.edu/~bagenal/1010/SESSIONS/13.Light.html http://www.xylenepower.com/ http://spaceguard.esa.int/NScience/n...y/emission.htm All of which indicate a temperature of 280K and peak clearly at...

Hello, can someone explain how a line spectrum works. How do they provide evidence of energy levels in atoms? I would have thought that energy levels are to do with a different concept of Bands (Valence, Conduction) so how does a line spectrum provide evidence? :confused:

I used to think that the frequencies obtained by a Fourier Series or Transform from a signal in the 'time domain' were simply a consequence of our mathematical system. In other words, it is a consequence of the fact that sinusoids are used to recreate or synthesize the signal. It's just an...

for hv>>kT how does exp(hv/kT) compare to 1? I understand hv >>KT leads to an exponential fall in brightness but why did Planck introduce 1 in his equation. and only for values hv<<kT can this exponential be expanded! Thanks for any help!

I'm studying astronomy and I'm have these problems to solve, but there are a few things I don't really understand, hopefully someone can explain these things to me. 1. Why are spectra of molecules more complex than spectra of atoms? Is it because molecules can be excited in different ways...

1. How does wavelength affect line spectra (the spacing)? I did some research and found the wavelength of green light to be 510 nm and red light to be 650 nm. So for the experiment I looked through slits (such as 2, 2, 6 (which represents 2 slits, 2 points wide, and separated by 6 points)...

I have several questions that I would appreciate if you guys could help me with, I want to understand these conepts as well as possible. In my chemistry textbook it states that the atoms of each element have a spectral signature, and each atom emits a certain wavelength of radiation, for...

My understanding of analyzing emission spectra is that when the quantum number of an electron decreases (i.e. when it falls closer to the nucleus) it emits energy. I understand that this is a very basic understanding but I have not yet made it to college, so please bear with me. :) Now, what I...

Why is it that LEDs do not sharper spectra? I've been considering this recently, and was wondering if it was due to the uncertainty principle (like homogeneous broadening in a laser) or is it due to a fluctuating band gap? I've searched high and low and can't find any explanation for the...

I'm doing research on window functions (such as: rectangular, Hanning, Blackman, etc), but am having trouble with respect to the energy loss associated with each. I know that applying the window causes energy loss in the spectra of interest, and for the Hanning Window and Hamming window...

erm a simple question. If all light comes from the electrom-photon interference in an atom, that means that we can't obtain a continuous spectrum theoratically. How then is an absorption spectrum possible??

I was doing a test about rydberg constants using H2 and Hg light spectrum And in the spectrograph I found that H2 have three spectra and the Hg have 5 spectra And I DON'T KNOW WHY H2 have 3 lines and Hg have 5 lines? (Scientifically). I know it is the numbers of the electrons that...

Homework Statement An atom of element Q can only absorb two photons of frequency 6.40E14 Hz and 9.05E14 Hz. Explain how atoms of element Q could absorb or emit photons of particular frequencies.2. The attempt at a solution OK I think I am missing something in my understanding of absorbtion...

Hello everyone, I'm new to this forum and in fact have never used a forum before so this is a bit new for me. I'm a high school student from NZ, and some of the course I'm doing has flummoxed -not in that I can't rattle off the generic answer, I just don't quite understand. The main area in...

Hi, I am calculating the spectra of a small molecule - benzen with nitrogen group attach. I have some experimental data of the molecule IR and raman. I use DFT B3LYP with TVZ as basis set when I compare the modes and are a lot of differences between the two. 1. Would it help to increase...

hi, I am trying to interpret some data which have been calculated for IR/Raman but I don't know how to interpret them exactly. The schema says mode \nu 1 b_u 82 1 a_g 216 2 b_g 239 I presume that the u/g are gerade/ungerade from the bonding/antibonding wave functions but how to...

Homework Statement Is it possible to use electromagnetic radiation to ionize atoms. To do so, the atoms must absorb the radiation, the photons of which must have enough energy to remove an electron from an atom. What is the longest radiation wavelength (nm) that can be used to ionize the...

So I have a spectra of CO that I need to interpret. My guess is that the spectra will depend on the vibrational and vibrational factors but how could I see that? I mean what will that come out like in the Fourier spectra? any tips on this our a site where I can read more about it is...

Will the spectra of the transmitted and received signal be different as a result of multipath reflection and noise?

Homework Statement A molecule with angular momentum L and moment of inertia I has a rotational energy that can be written as E=\frac{L^2}{2I}. Assuming that angular momentum is quantized according to Bohr's rule L = n\hbar, find the wavelength of the photons emitted in the n=2 to n=1...

1. Doubly ionized lithium Li2+ (Z = 3) and triply ionized beryllium Be3+ (Z = 4) each emit a line spectrum. For a certain series of lines in the lithium spectrum, the shortest wavelength is 1222.2 nm. For the same series of lines in the beryllium spectrum, what is the shortest wavelength...

Hi, We are using Varian Unity Inova 500 MHz NMR instrument.When we are taking 31P and 19F spectra we do not use any reference sample as like TMS etc. Our customer says us that they are not interpreting these spectras without reference. Which reference can we use for these spectras and how can...

Simply put, does it ever change? That is, does the line spectrum of a particular element or compound ever change? I've been searching all over, but I'm getting different answers!

Hi All, I am working on a sensitivity model for a short wave IR spectrometer. And I have come up to a few questions that I had never thought of before and that seem really interesting (and I still don't know the answers, so it'd be great if anyone had any insight!) Well, I need to look at an...

Hi there. I'm new to this board so please excuse if this is misplaced, there seems to be too many places to choose from. While browsing my computer I found a little program I wrote when doing year 12 physics that was based on the textbook material about ionization energies. It recurssively...

I have tree files of IR spectra but I cann't open them, because I have no suitable software. I need to open them. does somebody knows some kind of freeware which I can use to open this files. or if somebody can I will send this files to open and copy them into MS Word and send them back to me...

I need help on this problem that asks me to solve for n_1 and n_2 (the initial and final quantum numbers). This is the given information (the line spectra for Hydrogen): color red known wavelength: 656.4 nm color turquoise known wavelength: 486.3 nm purple...

Can anyone send me a picture of graph absorption spectra of 2,3-dimethylindole? The graph should be accurate (from a spectrophotometer) Thanks

Hello there, if I have a impulse train as f(t) with a frequency of 100 khz, and cos(w_0*t) = g(t) with frequency of 10 khz, how do I go about determining the signal spectra, (i.e. harmonics n = 1,2,3...)? I determined the Fourier transform, but I get stuck as to what to do with it. :confused...

I was wondering why Henry Moseley ploted \sqrt{f} vs. Z instead of just f vs. Z. I'm guessing it is because this way, the graph of \sqrt{f} vs. Z would be linear? But if it was just f vs. Z, wouldn't the equation just be exponential? Also, what is the significance of the L seriese and the K...

In Sakurai: The state ket for an arbitrary physical state can be expanded in terms of the |x'> |\alpha>=\int dx'^3 |\mathbf{x'}><\mathbf{x'}|\alpha> (where the |x'> are the eigenkets of the position operator, \hat{x}|x'>=x'|x'>). (Sakurai 1.6.4, p. 42) My question is about how this integral is...

In L. I. Schiff book, one can follow his derivation of the Hamiltonian from Dirac relativistic equation and obtain the following.. \left[\frac{\vec{p}^2}{2m}+V-\frac{\hbar^2}{4m^{2}c^{2}}\frac{dV}{dr}\frac{\partial}{\partial r}+\frac{1}{2m^{2}c^{2}}\frac{1}{r}\frac{dV}{dr}\vec{S}\cdot...

Please check my solution and I need help on understanding the second part of the question. Q:Obtain the complex form of the Fourier series of the sawtooth function. f(t) = \frac{2t}{T} \ \ \ 0 < t < 2T\\ So if the period is 2l = 2T then l = T \\ c_n = \frac{1}{2l} \int_{-l}^{l} f(x) e^{in\pi...

i'm about to tear off all the hair on my head, learning about line spectra... i got the lyman,balmer and paschen series in my textbook and the formula for it. but how do i apply it in a physics question? like for example if i have an electron that is excited to the n = 6 state, which formula...

Why does neon have more spectral lines than helium? Is the atomic spectrum based on an element's electron configuration?

Hi! to everyone on the forum. I am new and did not really know where i should of posted this thread its not homework its just a question i have. A friend of mine asked me a question about a book he read about (atomic spectra and atomic structure by Gerhard Herzberg). Gerhard Herzberg said...

Hello, A friend of mine has synthesized a compound with pentafluorophenyl groups, and is willing to characterize it via an additional 19F-NMR. However, the person responsible for recording NMR spectra is inexperienced in 19F-NMR, so we need help on recording the spectra. We have...

Consider the Lyman photons for Hydrogen-like atoms with Z greater than one. Which of these atoms have Lyman alpha photons in the 1)visible 2)UV 3)X-ray and 4)gamma-ray parts of the spectrum? Can list ranges of values of Z in the answers. My thoughts are to use 1/lambda=...

Why don't stellar spectra show absorption lines for carbon, oxygen or nitrogen if they are such abundant elements. Is there a 'spectral type' that does? Thanks Dave

Hi all, i am studying the physics of Raman Spectra. Was able to understand the origin of Vibrational Raman Spectra... which was an effect due to the change of polarizability with internuclear distance due to molecular vibration. But, i still yet to figure out why rotation of molecules can...

Hi, i have a question, if we imaging that the universe is static and not expanding, what observation would be made in regards to red shifts in galaxy spectra?

just been learning how to produce x-rays by firing electrons at heavy atoms, but i am a tad confused about the x-ray spectra graph with 'intensity' on the y and 'wavelength' on the x. it shows that the minimum wavelenth is produced wen intensity=0. how is this possible?

An emission spectrum can contain wavelengths produced when an electron goes from the third to the second leve. So could you see this like in the absorption spectrum? Why?

Is it possible to see the radio spectra, X-ray, or microwave etc like birds can see the UV spectra? If so what might/does it look like? Thanks

I got a spectra I need to interpret. It is used to calculate the rotational speed of Jupiter. However, altough the computer indicates the doppler shift, I don't see anything (see photograph). I wonder if anyone could enlighten my stalled mind? :smile: I suppose when I figure out the...