De broglie wavelength Definition and 146 Threads

I cannot understand why the electron orbit should be an integer multiple of De Broglie wavelength. Why should the wave path "fit" the electron orbit for it to be stationary?

The question as stated in title, why?

Am I correct in thinking that the quantum mechanical de broglie wavelength explains relativity's contraction of matter? because lambda = h/p, as the velocity of say a proton increases, the momentum also increases, and the wavelength should get smaller because lim p-->infinity of h/p = 0. At very...

De broglie wavelength of fast moving particle--help please! Homework Statement A particle moving with kinetic energy equal to its rest energy has a de Broglie wavelength of 1.7898 *10^-16 m. If the kinetic energy doubles, what is the new de Broglie wavelength? Homework Equations...

Homework Statement A certain crystal has a set of planes 0.33 nm apart. A beam of neutrons strikes the crystal at normal incidence and the first maximum of the diffraction pattern occurs at ∅= 38°. What is the de Broglie wavelength of the neutrons? Homework Equations nλ = Dsin∅ where D...

The atoms in a gas can be treated as classical particles if their de Broglie wavelength is much smaller than the average separation between the particles. Compare the average de Broglie wavelength and the average separation between the atoms in a container of monatomic helium gas at 1.00 atm...

Homework Statement In quantum mechanics the de Broglie wavelength of an object depends on its momentum according to λ=h/p where h is Planck's constant. Protons of charge e and mass m are accelerated from rest through a potential V. What is their de Broglie wavelength? A) 2h/\sqrt{}meV...

As we know that the properties of nanoscale material are quite diffrent from the bulk's. But what's the threshold of the size, or what the upper limmit where significant difference can be observed? The De Broglie wavelength or the Fermi wavelength of the electron in material? How to understand that?

Homework Statement What is the De Broglie wavelength of an electron with KE= 8.5 eV? Homework Equations λ=h/p KE=0.5mv2 p=mv The Attempt at a Solution I converted 8.5 eV into joules: 8/5 eV × 1.602e-19 J = 1.3617e-18 Then used it for KE to solve for v: I got 1729006.11...

Homework Statement http://img580.imageshack.us/img580/7492/50177994.jpg The Attempt at a Solution I first attempt part (a) since both parts are similar: (a) I need to know "v" in order to use the following equation to find the de Broglie wavelength: \lambda = \frac{h}{p}...

We can calculate a de Broglie wavelength for a particle with momentum p. My question is does this apply to the lateral size of the particle? Perpendicular to the motion the momentum is zero. What can we say about the size of the particle in the perpendicular direction?

Homework Statement The Attempt at a Solution I don't see how they got sqrt(1.5/E) I tried it like this Not the right answer.

While deriving De-Broglie wavelength we equate mc^2 to hf and then for electron we change c to v but as far I know mc^2 is rest energy then how could c be converted into v for electron.Shouldnt it have the same rest energy?

I'm reviewing for one of my final exam and I can't seem to figure out this problem: Find the Debroglie wavelength of an electron with a KE of 40 ev. I got an answer of 3.9 x 10^-10 m. I keep getting it wrong and I'm not sure what to do. Thanks in advance!

i want to know the practical application of De Broglie wavelength in the life !

Homework Statement (a) Find the kinetic energy of an electron whose de Broglie wavelength is equal to 0.63 Å, a typical atomic size. Ke = 379 eV (b) Repeat part (a) for an electron with a wavelength equal to 1.7 x 10-15 m, a typical nuclear size. Ke = _____eV Homework Equations...

Homework Statement In the Bohr model of the hydrogen atom, if the electron is in the second orbit with a radius of 2.12 Å. What is the de Broglie wavelength of the electron? Homework Equations λ = 4h^2ε/me^2 The Attempt at a Solution I found this equation hunting around online and...

Find the kinetic energy of the following particles that each have a de Broglie wavelength of 0.50 nm.? (a) photons ____eV = 2480eV (b) electrons ____eV (c) neutrons ____eV (d) α particles ____eV i know E= hc/wavelength which = a and after that I am stuck i know that the wavelength =...

Hello there, If an object has a mass of 1 in arbitary units, and it's velocity is zero relative to you, what is the de Broglie wavelength? Shouldn't p be zero in this case? Or am I missing something related to intrinsic energy and momentum? Thank you very much.

Homework Statement Find the de Broglie wavelength for an electron with v=0.001c. Find the angular width of the central bright fringe in a double slit experiment, with the separation of the two slits d=50nm. Homework Equations wavelength = h/mv d sin(theta)=n*wavelength The...

Photons are blue-shifted as they accelerate in free-fall toward the earth. When an electron or positron is conceptualized as a wave using de Broglie's equation, are the de Broglie wavelengths of the electron or positron shortened (blue-shifted) as they accelerate toward the Earth in free-fall...

Why is the de Broglie wavelength sometimes larger than the particle it describes? Thanks, Jake

Question-A certain crystal has a set of planes spaced 0.376 nm apart. A beam of neutrons strikes the crystal at normal incidence and the first maximum of the diffraction pattern occurs at a scattering angle (i.e angle between incoming neutrons and reflected beam) of 41.4 degrees. What is the de...

i was working on atomic structure and i stuck here. how can a wave be associated to any material? is it related to wavelength of colur it emits or is it the wavelength of vibrations after it has been stuck by something? what is it??

Homework Statement To "obeserve" small objects,one measures the diffraction of the particles whose de Broglie wavelength is approximately equal to the object's size. Find the kinetic energy(in electron volts) required by the electrons to resolve c) a nucleus of size 10fm. Homework...

I have a few questions: 1. 'small smoke particles in air are seen under a low magnification microscope to move randomly at a speed of 0.10mm/s. The speed of sound in air is 330m/s. Estimate the mass of the smoke particles. I cannot make the link between speed of particle and speed of sound -...

Homework Statement An electron in the first Bohr orbit of a hydrogen atom (a_0=5.3*10^-11m) has a KE of 13.6 eV. Express the de Broglie wavelength for this electron in multiples of the atomic circumference. Homework Equations lambda=h/p =h/(sqrt(2mqV) The Attempt at a...

Homework Statement What is the de Broglie wavelength of a neutron traveling with a momentum equal to 300 \frac{\text{MeV}}{\text{c}}? Homework Equations \lambda = \frac{h}{p} The Attempt at a Solution p = \frac{300 \cdot \left( \left(1\times10^6 \right) \times...

I've been studying quantum physics for a little over a semester now and I'm having trouble wrapping my head around the physical significance of matter waves. The derivation also confuses me because it states the momentum of particle with mass as mc, which is only true for a massless photon. I...

Just a random thought: is it not possible for a person to move slow enough to have an observable de Broglie wavelength? For example a person moving at around 10^-30 m/s should have a wave nature that is very observable.

Homework Statement By estimating the De Broglie wavelength and the inter-particle spacing, find whether the following systems of particles are degenerate: (i) a gas of neutrons in a neutron star with mass density 10^17 kg/m^3 at the temperature of 10^8K (ii)a gas of oxygen molecules at...

Homework Statement Show that the de Broglie wavelength of a particle of mass m and kinetic energy KE is given by \lambda = \frac{hc}{\sqrt{KE(KE + 2mc^2)}} Homework Equations The Attempt at a Solution I know: KE = {\gamma}mc^2 - mc^2 = pc - mc^2 But from here I am...

E=mc^2 and E=hf. In Special Relativity, how can y=h/p be derived from E=hf?

Homework Statement In his presentation of the de Broglie wavelength and the wave/particle duality, my quantum prof. has an exercise: "Find the de Broglie wavelength of a molecular vibration. Do quantum or classical laws apply?" Homework Equations wavelength = h/(momentum) ...

Hello, I've always wondered about the "relativity" of the De Broglie wavelength. The wavelength depends on the momentum of the specific thing we are observing, thus on different frames of reference(F.O.R from now on :P) we might get different answers. I have been looking through the web to...

Homework Statement Calculate the de Broglie wavelength of an oxygen molecule (molecular mass 32)in air at room temperture. Homework Equations P = h/ \lambda P= mv E= hv = 1/2mv^{2} = P^{2}/(2m)The Attempt at a Solution hv = 1/2mv^{2} h = 1/2mv If v = P/m then h = mp/2m so p= 2h This...

I can work out the wavelengths fine, but I am unsure of the answer to the second part, any help would be much appreciated

Homework Statement What is the de Broglie wavelength of a neutron whose kinetic energy is equal to the average kinetic energy of a gas of neutrons at temperature T = 17 K? Homework Equations lambda = h/p = h/mv. The Attempt at a Solution Well first I tried taking the h =...

Homework Statement Earth has the mass 6 · 10^24 kg and the orbit radius r = 1.5 · 10^11 m. (a) Compute its de Broglie wavelength. (b) Apply de Broglie quantization condition as in the case of the Hydrogen atom and compute the quantum number n for the orbit of Earth. (c) What is the...

Homework Statement Find the de Broglie wavelength of an 8 MeV proton. Homework Equations y = h/p where y is the wavelength p = mv K = Eo/sqrt(1-v^2/c^2) where Eo is the rest mass and K is the kinetic energy The Attempt at a Solution I make the assumption that "an 8 MeV proton"...

Hi there, Is it possible if an object were to hypothetically gain enough momentum such that its de Broglie wavelength is equivalent to, say, some light in the visible spectrum, that the object would emit light? Thanks!

OK so you get to the matter wave equation 'lambda = h / p' using E=cp - which describes the energy for massless particles. I can understand this holding for when cp>>mc^2 , but not for when the mc^2 is comparible. Any help?

Wavelength of an electron Homework Statement -Electron has 3.00 MeV (or 4.8*10^-13 Joules) -it's relativistic -finding λ. Homework Equations h=6.63*10^-34 λ=h/p (obviously) And I'm not sure if they're needed, but the relativistic eq's are: KE = mc^2/sqrt(1-(v/c)^2)...

Homework Statement an electron is moving at 2.5 x 105m/s. Find the electron's De Broglie Wavelength. Homework Equations De Broglie relates wavelength of electron waves to momentum of the electron by lambda = h/p where h is Planck's constant. The Attempt at a Solution given the...

Homework Statement What was the significance of the de Broglie equation? Homework Equations p = h/λ p = mv The Attempt at a Solution It says that not only do waves act as particles, transferring energy and momentum to matter only at localised points, but moving particles (e.g...

Homework Statement The potential-energy function U(x) has the constant value U_0 in the interval 0 < x < L and is zero outside this interval. An electron is moving past this square barrier, but the energy of the electron is greater than the barrier height. If E= 6 U_0, what is the ratio...

Homework Statement In one of the classes, a recent experiment showing the interference of C60 molecules using a double slit apparatus was discussed. (a) If the average velocity of the C60 molecules is v= 200 m/s, calculate the De Broglie wavelength for a C60 molecule Homework Equations...

Homework Statement What is the de Broglie wavelength of this electron? Given is 500 eV Homework Equations KE= 1/2 mv^2 1 eV=1.602x19^-19 J The Attempt at a Solution I converted the 500 eV to 8.01x10^-17 via the given conversion. Now I'm stuck.

In Classical Mechanics the derivative of Kinetic energy with respect to velocity is momentum, so I was wondering if this is valid: In this L is lambda or wavelength and h is Planck's Constant. E=hf, therefore E=h(v/L) This means that dE/dv=h/L.(h and L are constants and the derivative of...

Homework Statement De Broglie wavelength What is the De Broglie wavelength of the 1.0-TeV (1TeV=1012eV) protons (mpc2=938.3MeV) accelerated at the Fermilab Tevatron accelerator? These high-energy protons are needed to probe elementary particles [Hint: You need to use relativistic formula, but...