Wavelength and Frequency Calculations ( Read ) | Chemistry | CK Foundation
Explains the anatomy of a wave and the relationship between wavelength and frequency. In physics, the wavelength is the spatial period of a periodic wave—the distance over which the The range of wavelengths or frequencies for wave phenomena is called a spectrum. the phase speed itself depends upon the frequency of the wave, making the relationship between wavelength and frequency nonlinear. Frequency period formula angular frequency cycle per second hertz Hz amplitude equation time wavelength Hz to millisecond ms cycle duration time period relationship cycle duration The calculator works in both directions of the ↔ sign.
So I'm gonna draw in a particle of light which we call a photon, so this is massless, and the photon is going to hit this electron, and if the photon has enough energy, it can free the electron, right? So we can knock it loose, and so let me go ahead and show that.
So here, we're showing the electron being knocked loose and so the electron's moving in, let's just say, this direction, with some velocity, v, and if the electron has mass, m, we know that there's a kinetic energy.
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The kinetic energy of the electron would be equal to one half mv squared. This freed electron is usually referred to now as a photoelectron. So one photon creates one photoelectron. So one particle hits another particle. And, if you think about this in terms of classical physics, you could think about energy being conserved. So the energy of the photon, the energy that went in, so let me go ahead and write this here, so the energy of the photon, the energy that went in, what happened to that energy?
Some of that energy was needed to free the electron. So the electron was bound, and some of the energy freed the electron.
I'm gonna call that E naught, the energy that freed the electron, and then the rest of that energy must have gone into the kinetic energy of the electron, and so we can write here kinetic energy of the photoelectron that was produced.
So, kinetic energy of the photoelectron. So let's say you wanted to solve for the kinetic energy of that photoelectron.
So that would be very simple, it would just be kinetic energy would be equal to the energy of the photon, energy of the photon, minus the energy that was necessary to free the electron from the metallic surface. And this E naught, here I'm calling it E naught, you might see it written differently, a different symbol, but this is the work function.
Let me go ahead and write work function here, and the work function is different for every kind of metal. So, it's the minimum amount of energy that's necessary to free the electron, and so obviously that's going to be different depending on what metal you're talking about.
All right, let's do a problem. Now that we understand the general idea of the Photoelectric effect, let's look at what this problem asks us. So the problem says, "If a photon of wavelength " nm hits metallic cesium So we know what E naught is here. What we don't know is the energy of the photon so that's what we need to calculate first.
And so the energy of the photon, energy of the photon, is equal to h, which is Planck's constant, times the frequency, which is usually symbolized by nu. So, we got the frequency, but they gave us the wavelength in the problem here. The range of wavelengths sufficient to provide a description of all possible waves in a crystalline medium corresponds to the wave vectors confined to the Brillouin zone.
Wavelength and Frequency Calculations - Chemistry LibreTexts
It is mathematically equivalent to the aliasing of a signal that is sampled at discrete intervals. More general waveforms[ edit ] Near-periodic waves over shallow water The concept of wavelength is most often applied to sinusoidal, or nearly sinusoidal, waves, because in a linear system the sinusoid is the unique shape that propagates with no shape change — just a phase change and potentially an amplitude change. Sinusoids are the simplest traveling wave solutions, and more complex solutions can be built up by superposition.
In the special case of dispersion-free and uniform media, waves other than sinusoids propagate with unchanging shape and constant velocity.
In certain circumstances, waves of unchanging shape also can occur in nonlinear media; for example, the figure shows ocean waves in shallow water that have sharper crests and flatter troughs than those of a sinusoid, typical of a cnoidal wave a traveling wave so named because it is described by the Jacobi elliptic function of m-th order, usually denoted as cn x; m. If a traveling wave has a fixed shape that repeats in space or in time, it is a periodic wave. Be careful about using the exponent and unit combination.
Meters are longer than centimeters, so there are less of them used above.
Relationship between frequency and wavelength - Physics Stack Exchange
An interesting little light trivia: You might try and work out the proper calculation before checking the answer. What is the frequency of electromagnetic radiation having a wavelength of Check with your teacher to see if they have a preference.
Then, follow their preference. If I had done so, the value would have been 4. Note also that I effectively consider to be 4 significant figures.
Notice how the frequencies stay within more-or-less the middle area ofranging from 4.
If it isn't, then YOU not the teacher have made a mistake. What is the frequency of EMR having a wavelength of nm? EMR is an abbreviation for electromagnetic radiation.
Since one meter contains nm, we have the following conversion: What is the wavelength in nm of EMR with a frequency of 4.