# Tag Info

18

When an electron absorbs a photon, it remains an electron and the photon disappears. The electron energy and momentum are altered to account for the energy and momentum the photon was carrying. For a free electron, it will not be possible to balance energy and momentum simultaneously. There will have to be another interaction to make that work. If the ...

8

As Ross pointed out, two scenarios are possible: free electron / electron as part of an atom. They're treated in two totally different ways. Free electron: free electrons can't really "absorb" photons. They can collide with them, and some things can happen (this, for instance). Those types of collisions are described by QED and there are a bunch of ...

3

Earthing something means dumping the electron flow into the earth. Since the earth is so big, it can absorbe/give a practically infinite amount of charge without changing potential, this means that you can treat earth as a reservoir of ready to use electrons. If you plug the phase of your home power line into the ground (without safety devices in the ...

2

Part 1: Conceptual/physical intuition Since there is an electrostatic attraction between the 2 particles, then when they are apart they are at a higher potential energy then when they are together. Here's an analogy: Physically, this situation is like having a ball at the top of a hill overlooking a valley or well. The ball will roll down the hill and ...

2

Yes, it is possible. The simplest qualitative answer to this is that, at the microscopic level, the electrons in a conductor are dictated by quantum mechanics, which is inherently probabilistic. Velocities and positions are rarely ever totally excluded from a given value; it's just insanely unlikely for a single electron to attain that given value. ...

2

In this article electrons seen in a bubble chamber are shown. The spiral is an electron knocked off from an atom of hydrogen , a bubble chamber is filled with supercoole liquid hydrogen in this case. Th accuracy of measuring the tracks is of order of microns. The momentum of the electon can be found if one knows the magnetic field and the curvature. The ...

1

One model is to say that the atom is in an impenetrable spherical box, and solve for the wavefunctions. See Y P Varshni Accurate wavefunctions for the confined hydrogen atom at high pressures J. Phys. B: At. Mol. Opt. Phys. 30 No 18 (28 September 1997) L589-L593. The Fermi Contact Term (electron density at the nucleus) greatly increases as the size of the ...

1

Your value is within the range of literature values. Hydrocarbon Lithography on Graphene Membranes states "the Fermi wavelength of the electrons in graphene of 0.74 nm". Many references cite this value. Another reference says ~0.14nm.

1

Here, we shall discuss about relative permittivity $\epsilon_r$. Permittivity $\epsilon_s$ of a substance is the measure of the $resistance$ offered by a substance against the flow of electric field lines. Greater the value of $\epsilon_s$, fewer will be the number of electric field lines flowing through the substance. $\epsilon_r$ is defined as the ratio of ...

Only top voted, non community-wiki answers of a minimum length are eligible