Emission Definition and 546 Threads

Homework Statement I'm just curious to if I have answered this questions properly, and was wondering if someone can see if I should add more to what I have written, or completely change my answer. I'm pretty confident with what I've answered, but would like someone to check :) So to begin...

Actually I was studying on 2nd postulate of special relativity. There I saw Ritz's emission hypotheses says for an object moving directly towards (or away from) the observer at v metres per second, this light would then be expected to still be traveling at (c + v) or (c − v) metres. Now...

I have a question about Planck's Law. When I first read about it, I misunderstood it to mean that an object at a certain temperature would only emit a very narrow wavelength of light. But as I've looked into it further it appears as though everything in the universe emits a range of light that...

So the basic understanding I have of electron transitions for EDX, XES and other x-ray fluorescence techniques is that a transition from: L to K shell is named K\alpha M to K shell is K\beta N to K shell is K\gamma M to L shell is K\alpha etc. Grand, easy... google leads me to multiple diagrams...

Homework Statement I am writing my Extended Essay for IB, where I look at the possibility of obtaining accurate results in open system of a school, by accounting for all energy losses that occur during the investigation. Before conducting my experiments (which included an air track with two...

I've read the literature on the matter, but I'm still not entirely clear what's going on. The general idea I'm getting is: "You have a photon and an excited atom, photon comes near atom, stuff happens, and now you have two (identical) photons, also identical to the first, and traveling in the...

If a photon is emitted from the nucleus of an atom, and the atom is at rest is the photon and the atom entangled? If their spin angular momentum was zero before the emission. And is it possible to have an atom emit a photon from its nucleus and one of its electrons at the same time, and would...

This is my understanding; please, correct me if I'm wrong. If you bombard an atom with em-waves they will never break loose electrons until a certain threshold frequency. At this point the intensity of the light (or the amount of photons) striking the atom is proportional to the number of...

What is meant when it is said that an electron emits or absorbs a photon (leaving aside the aspect of heightened or reduced energy states and orbit changes, which I understand.) ? I see four possibilities: 1. Whether the electron is a particle or a wave or some combination of the two, the...

Am I right in thinking that the Heisenberg matrix interpretation describes emission, while the Schroedinger interpretation does not?

Ritz proposed in 1908 that SR was wrong, and that the speed of light would depend on the speed of the source according to Galilean addition of velocities, c+v. The review linked to from PF's sticky on the experimental basis of SR has a nice section on this...

When I study the mechanism of gamma-ray emission from pulsars, I got a statement saying that the quantity \sin^2\theta/r is conserved along any dipolar magnetic field line. Does anybody know how to derive this claim? Thanks in advance.

What is the proof that the total rate at which radiation is emitted by a black-body radiator is proportional to the fourth power of the temperature? Does this result come from Planck's radiation law? If yes, how?

I'm going to be very careful to avoid the word "greenhouse" because of the indefinite ban on discussions about climate change - I want to be clear, this isn't a topic about that. Part 1 - some gasses in the atmosphere absorb and emit radiation in the thermal infrared range. Gases like water...

Hi guys, this is a homework question, but i didnt think it belonged with the physics questions. I have the spectrum of a star, it has hydrogen gamma and hydrogen beta absorbtion lines, but a very very strong hydrogen alpha emission line. What is the significance of this, I would expect a...

Homework Statement Hydrogen atom with ionisation energy 13.6 eV is found to have an emission spectrum with lines at 1.89 eV, 10.20 eV and 12.09 eV. Draw a labelled diagram to show the energy levels of hydrogen atom by showing the transitions of electrons causing the emission of the lines...

2.3 \cdot 10^{10} atoms decay via alpha emission have a half-life of 150 min. How many alpha particles are emitted between t=30 min and t=160 min? \begin{flalign*} 150 &= \frac{\ln 2}{\lambda}\\ \lambda &= 0.046 \\ \\ K &= K_{0}e^{(-\lambda)(t)}\\ &= (2.3 \cdot 10^{10})e^{(-0.046)(30)}\\...

Homework Statement Complete this sentence. When doing Bragg scattering of x-rays off of NaCl, the first order K-Alpha peak has an energy that is ___________ the energy of the second order K-Alpha peak. Known Information It is known that the Intensity of the K-Alpha is greater than the K-Beta...

FIGURED IT OUT, PLEASE DISREGARD Homework Statement Find the shortest wavelength of the Lyman series for a triply-ionized beryllium atom (Be3+). Express your answer in nanometers using four significant digits. Homework Equations Rydberg's Formula: 1/\lambda=RZ2(1/n12 - 1/n22) The Attempt...

I'm dealing with this problem for an MCAT review: Following beta-emission by a neutral atom at rest, the respective linear momentums of the beta(-) particle and the resulting atom are shown below. (see attachment for message) It wasn't too difficult to see that an extra force is in play, and...

Homework Statement A transmission diffraction grating with 528 lines/mm is used to study the line spectrum of the light produced by a hydrogen discharge tube. The grating is 1.3m from the source (behind a hole in the center of a meter stick). An observer sees the first-order red line at a...

I have been reading up on radioactivity (Wikipedia). I keep coming across articles which talk about emission of Neutrons (during Plutonium decay, for example). Now I know alpha radiation is basically Helium-4 nuclei, but that consists of both Protons and Neutrons combined in a nucleus. What...

Say I have a 25MHz Crystal that's connected to a Microprocessor/Microcontroller or spread spectrum clock generator. Does the crystal emit Electromagnetic radiation at its fundamental frequency or it's harmonic frequencies? I keep hearing - " I see a peak at ~50MHz, it must be the 2nd harmonic...

Homework Statement hypothetical one electron searsium element. n=-20eV, n2=-10eV, n3=-5eV, n4=-2eV. photon emission n3>n2 and n3>n1 will eject photoelectrons from unkown metal, but photon emitted from n4>n3 will not. what are the limits (max and min values) of work function of the metal...

In stimulated emission how does the incident photon make release of other photon from another atom? advanced thanks.

Readers, Hi, I'm new here, and have a question that has piqued my interest, and have not found a solution elsewhere. My question is as such: is there an equation to determine the energy or frequency of the gamma ray emitted as a byproduct of radioactive decay for a given isotope...

Im just trying to figure something out here. Iv been working on some spectra stuff. Now, when I look at a gas, I see the spectra, but if I turn up the intesnsity, new lines appear? Where do these lines come from, as I am looking at the same game, just turned up intensity?

I'm sure I've heard the explanation for this before in class but I can't quite remember it: If electrons of an atom emit photons (ie lose energy), the orbits of the electrons will become smaller, right? If so, wouldn't the atom eventually collapse? What radially outward force keeps the...

Why in gamma ray emission there is no change in A or Z ? We know that in Alpha decay 2 protons and 2 neutrons are subtracted from the element. and in Beta decay there is change in atomic number by + or - 1. but why there is no any change in Gamma Decay in mass number A or atomic number. i...

Homework Statement A light bulb 10km away from you emits visible photons at a rate of 3x1018 photons/s. Assuming this is the only source of light (the whole place is dark), and your dark-adjusted retina has a diameter of 7mm, then how many photons/s hits your retina? Homework Equations...

Part of an experiment involved measuring the intensity of an X-ray beam through a piece of aluminium as a function of emission current of the X-ray source. I originally fitted a linear fit to my data (although it does start to level off at high emission currents). The marker however said that it...

I want to see if I understand these rules correctly. Us humans emit mainly in the infrared, that can be described by wiens law, but when visible radiation falls upon us, our body absorbs some part of the white light, but reflects whatever it doesn't. Smurf's for example reflect the blue part of...

On the web are some informed-sounding discussions saying that the various videos showing the appearance of the dots on the photo-sensitive surfaces can by no means guarantee that only one photon got through. A lot hinges on that, thanks for referring me to other posts which show certainty of a...

I am interested in learning the nature of the interaction between a photon and the atoms in a medium that has undergone population inversion that causes stimulated emission i.e. if an excited-state atom is perturbed by a photon (with an electric field of specific frequency), why does it emit an...

what type of ray does the bulb light emit?

If electric energy is supplied in the form of high voltage & low current & if the same energy is supplied in the form low voltage & high current will there be in difference in the photons emitted by the antenna?the frequency is same for both the cases.One electron can interact with just one atom...

Hi.. Does the Einstein's coefficient for spontaneous emission B depend upon the energy difference between the two levels?

I've been wondering about positron emission. If a neutron has more mass than a proton, how can a proton turn into a neutron by releasing a particle with mass? [PLAIN]http://img37.imageshack.us/img37/654/positronemission.gif (source:http://en.wikipedia.org/wiki/Positron_emission) Doesn't this...

Dear all I need to calculate the intensity of the spectral line. I have data from NIST website: wavelength, Aki (Einstein coefficient), gi, gk, Ei and Ek energy levels. How do i go about Thanks for your help

Homework Statement Determine the wavelength (in nm, to one decimal place) of the line in the emission spectrum of the He+ ion produced by a transition from n = 3 to n = 1. Homework Equations I used the Rydberg equation for this, although I'm not sure it is the correct one to use...

Hello, could you please help to clarifly the following. Do electromagnetic (e.g. light) and gravitational wavefronts caused by e.g. a supernova both appear at the same time seen from a distant observer perspective? Thank you!

I've looked at a few introductory treatments of the quantum harmonic oscillator and they all show how one arrives at the discrete energy values E_n = ( \frac {1}{2} + n ) hf \hspace {10 mm} n=0,1,2... usually by setting up and then solving the Schrodinger equation for the system...

Why do accelerating electrons (synchrotron) emit x-rays, but accelerating protons (cyclotron) don't? Both are accelerating/decelerating charges.

Hi all I'm unsure about something and so would like to pose the following question. When an electron moves to a lower state it emits energy in the form of a photon. But in order to get excited into this higher state it must first receive a minimum amount of energy. Is the energy received...

From what I have learned so far, it appears that a light emission orthogonal to motion acts exactly like a Newtonian massive particle with conserved longitudinal momentum. Is this correct? If so it would seem to be a cosmic coincidence of monumental proportions. Having given it some...

I seem to have some trouble finding a definite answer by searching the following: It is my understanding that when an electron is excited to a higher energy state, it will spontaneously decay back and emit a photon. My questions are: Is the wavelength of light required to excite an...

Hi, quick one: In my nuclear physics notes it says alpha emission is often the only light particle emission that takes place due to its very high binding energy. What I don't understand is that how come the nucleus wants to retain binding energy? I would have thought that it wants to get...

My textbook says "absorption yields color. emission yields fluorescence" - can someone explain what that means exactly. I know color is when something absorbs all wavelengths except one, which gets reflected and produces color. If it helps... the chapter is on bohr's model.

About the intensity of x-ray emission spectrum of Molybdenum as a function of wavelength for various applied voltages: Explain fully: 1) the production of continuous radiation emitted 2) the absence of radiation of wavelength shorter than the minimum wavelength 3) the presence of the...

Hi! I need to know what's the "hard bremsstrahlung emission". I googled it but it only showed papers (and few because my university don't have access to many) on experiences that at some point mention this effect but don't explain it. I know what's bremsstrahlung emission, just don't know...