Recent content by Chem.Stud.

I see where I went wrong. I have managed to get the correct answer. Thank you for your help!

Hi there! I have tried for hours to calculate the commutator of angular momentum in the differential form, but I cannot get the correct answer. This is my first experience with actually checking if two operators commutes, so there may be some beginner's misunderstandings that causes the...

Thanks, I appreciate your help. Approximation is new to me, but I I followed your reasoning most of the way. I have a few questions, if you do not mind: \psi '' + x^2 \psi = 0 I understand how you came to this equation, but I did not follow your reasoning after. We have to consider...

My background in mathematics is not very broad, and I have not ever worked with Hermite polynomials. Would you care to show how that limit develops? My calculus experience is quite limited, unfortunately. H_n(x) = (-1)^ne^{x^2} \frac{d^n}{dx^n} e^{-x^2} I found this on wikipedia, but it...

Hi folks! Apparently \Psi(x) = Ax^ne^{-m \omega x^2 / 2 \hbar} is an approximate solution to the harmonic oscillator in one dimension -\frac{\hbar ^2}{2m} \frac{d^2\psi}{dx^2} + \frac{1}{2}m \omega ^2 x^2 \psi = E \psi for sufficiently large values of |x|. I thought this...

Oh. I thought in the lines of that since the relativistic energy is expressed in terms of the rest mass, that equaled the rest energy, i.e. the energy of the electron at rest. If I just substitute E^2 with E = \sqrt{p^2c^2+m_0^2c^4}, I end up with: \lambda = \sqrt{\frac{h^2c^2}{p^2c^2}}...

Yes, I did it! Starting from scratch with equation 1, which was \lambda = \sqrt{\frac{h^2c^2}{E^2 - m_{0}^2c^4}} You said E represents the total energy, the sum of the kinetic energy and the rest energy. The rest energy is given as the equation already stated at the beginning...

Ah, yes, E = pc is a special case for the einstein relativistic energy. I will give it another try.

Thank you! I updated the post just before you answered. But I not sure I have made it. My expression leaves me with a complex wavelength. edit: Man, it happened again!

[I could not fit the last "e" into the title] Hi! I am writing a report on TEM, and was asked to consider the effect of accelerating voltage on the resolution. Since resolution in the light microscope is limited by the wavelength of visible light, we obtain much higher resolutions in a TEM...

I think I understand what you are saying. That way (Figure 1) of modelling the rays only serves the purpose of calculating the distance between the crystal planes. But why does bragg's criteria for constructive interference apply to Figure 2, when the geometry is different?

Bragg's Law is well-known, and looks like the following: nλ = 2d \cdot sin(θ) , where d is the distance between the two crystal planes. This equation, or criteria, describes when constructive interference happens and an intensified, reflected ray can be measured at the same angle as the...

Ahh, that makes sense. Thank you for your help.

This is very interesting. In Norway, no one calls their Professors by their titles. The Professors dress casually and allow computers, cell phones (with sound off) and moderate talking in large auditories. I was used to this. Then, I signed up for a class in academic writing. The Professor...

Hi: I am taking a radiochemistry class, and I am confused by beta plus decay. (1) p --> n + positron + electron-neutrino The mass of a proton is less than the mass of a neutron. In addition, the neutrino has mass as does the positron. (2) E = mc2 There must be come sort of...