Spectra Definition and 285 Threads

Metals of Transition series influence in proton RMN spectra First of all, Greetings to everyone My question is simple but a bit able to create confusion i can't explain myself right so I'm going to try... The question is how can the fact of a metal being of the transition serie os periodic...

Hello I'm currently studying the reaction of anisole with hexacarbonylchromium, and experiment shows the displacement of 2 of the carbonyl ligands with the anisole group, forming a 2-η ligand with the chromium ion. After refluxing to obtain the crystals, IR and nmr spectra of the sample...

Why the rutherford atomic model can't explain the line spectra of the hydrogen atom?

I was not sure if I should post this here or in the Atomic forum (hope its in its right place). My task is to plot the "synthetic" emission spectra with help from data provided by the hitemp database (hitran database: http://www.cfa.harvard.edu/hitran/). So, I have several question that have...

Recently, I read one book about quantum chaos. In it, random-matrix theory is used to describe the quantum signatures of chaos. Firstly, a new set of levels {E’1,E’2,E’3,...} is gained by unfolding the vibrational spectrum {E1,E2,E3,...}...

I know there are many ways to identify the spectra but, what are the advantages and disadvantages of using the first and second order lines to identify spectra? Please Help! If u don't want give me answer then suggest me some links. Thanks

Hi, I am wondering what is the difference between 1D spectra and 2D spectra? I see many documents talking about one of these 2, but I couldn't find any clear definition...

I'm trying to teach myself quantum mechanics from Dirac, and I'm having trouble justifying some of the maths, in particular how we can just jump out of the confines of a Hilbert space when it's convenient. Dirac rather liberally talks about observables that have a continuous range of...

Homework Statement I am analyzing power spectrum of the series obtained using different approaches. I have 100 points series. First method is obtaining power spectrum by taking squared FT of series and divided by the period. Second method is taking IFT from ACVF of the series. In both cases...

So I have a power spectrum of a given function, which is supposed to be a superposition of four sinusoidal terms with frequencies that range from 1xomega to 4xomega. My spectrum looks something like this: http://upload.wikimedia.org/wikipedia/commons/4/4f/Triangle-td_and_fd.png What exactly...

Homework Statement An astronomer is trying to estimate the surface temperature of a star with a radius of 5.0* 10^8m by modeling it as an ideal blackbody. The astronomer has measured the intensity of radiation due to the star at a distance of 2.5* 10^{13}m and found it to be equal to 0.055...

Wich are the differences of the spectra of H and He ionized?

Hi everyone, What does the "relative intensity" mean when we talk about spectra? The intensity relative to what, the background? Thank you

In my astrophysics book (Astrophysics, Nigel Ingham), there are intensity-wavelength graphs for line spectra (both emission & absorption). On the y-axis, relative intensity is plotted. But on the x-axis, frequency and not wavelength is plotted. Why is this? If I wanted to convert this graph to...

Don't exactly know where to put this but how would one examine the spectra of a metal ore to find what is in it? That being, not using a mass spectrometre.

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...

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/neo/dictionary/emission.htm All of which indicate a temperature of 280K and peak clearly...

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...

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??

Homework Statement How do you show that in spectra taken along the equator of a rotating rigid sphere the spectral lines are tilted but straight? Homework Equations There were no equations given in the problem, so I guess you can use whatever equations you know. The Attempt at a...

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...

Homework Statement If the thermal population of the rotational levels is given by: Nj/No = (2J+1)*exp(-hcBJ(J+1)/kT) Calculate which state has the highest thermal population at a given temperature T. Calculation needs to be shown, not just a result. Homework Equations Nj/No =...

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...

In the hydrogen atom, an electron is in the 3d state. (i) Find the orbital angular momentum of the electron (in units of n =3, l = n - 1, l = 1. L = [sqrt( l (l + 1) )]hbar therefore L = sqrt(2).hbar (ii) Find the energy of the electron (in eV). En = -13.6ev / n^2. E = - 13.6eV / 9 (iii)...