Levels Definition and 499 Threads

From statistical mechanics in zeemansky's book . He states that it's easy to see that for a closed system the no. Of degenerate states ##g_i## for energy level ##E_i## is greater than the number of particles ##N_i##occupying that energy state. I can't find a mathematical proof for it. Can I...

I've just started with statistical mechanics and arrived at the part where they relate entropy to the number of microstates for a given system. The derivation starts of by adding an amount of heat ##\delta Q## to a system and observing the resulting change in internal energy : $$\delta U =...

I will be giving O levels in two sitting for may'17 and jan'18 . I aim to be a heart surgeon. I plan on taking Biology but I am confused if I should take Human biology or not. If I take , I will only be left with 6months of private coaching , I am also scared if I'll be able to bring good marks...

Homework Statement A unknown nuclide emits four alpha particles with energies 8.54, 7.04, 6.38, and 5.10 MeV a) what are the nuclear energy levels of this nuclide b) What are the possible gamma ray energies that should be observed[/B]Homework EquationsThe Attempt at a Solution I was trying...

Homework Statement In the earliest circular planetary model of the atom the electron and proton orbited a common centre. The electrostatic forces alone provided the force field. However an accelerating charged body will send out electromagnetic waves and the orbiting charges would consequently...

Derivation of energy levels in a quantum harmonic oscillator, ##E=(n+1/2) \hbar\omega##, is long, but the result is very short. At least in comparision with infinite quantum box, this result is simple. I suspect that it can be derived avoiding Hermite polynomials, eigenvalues, etc. I understand...

I have previously learned about the energy level calculation of some diatomic molecules, such as N2 and CO. Now I need to calculate the spherical top symmetric molecules like CH4. But I cannot find the force constants for it either, can anyone give me some suggestions about this?

Homework Statement Homework Equations Fluid in rotation The Attempt at a Solution This exercise is quite different from the classic one of fluidi in rotation. Before rotation starts the height in one branch is bigger than in the other, so I do not really know how to approach the problem...

Why is is true that for a given system, if I fix the volume and increase the temperature, you'd expect the occupancy of the energy levels to change, but not the levels themselves? Can I think of this in terms of the fact that the boundary conditions for the solution of the TISE are fixed, such...

So if energy levels, or eV of electrons, do not change with molecular bonding, how are electrons influencing each other.? In glass, when individual atoms of silicon, sodium, and calcium come together, to form glass, the molecular bonding does not change the energy levels of the electrons for...

So in glass, transparent liquids, and plastics is the eV for the electron known to science. The eV levels for electrons in gases are known like in hydrogen, and helium, but are they known for glass, and transparent liquids, and plastics. Or is it just too discernable to get. I am grateful for...

How can a electrons energy levels increase, and decrease in eV As atoms come together to form molecules the energy levels of electrons change in eV, but are there other ways a electrons eV can change. Can heating a material change the electrons eV level, when visible light hits the electrons...

(sorry for my poor english.) is there a math book for learning mathematics from the beggining until university level, like there's University Physics for physics?

Hello! I am not sure how I would go about calculating the time it takes for a radioactive element to decay to safe levels. I know of the decay formula (N=No*e^(-kt)) and K =ln2/t(1/2). I believe calculating the time until an atom has decayed to safe levels has to do with the activity (Bq) A=kN...

So I'm trying to figure out how we got the allowed vibrational energy levels for a diatomic molecule by approximating it with simple harmonic motion. I do know how to use the uncertainty principle to get the zero-point energy: We know that the potential function is ##V(x) = \frac{1}{2}mx^2##...

how does the quantum number n in the wavefunction equation for a particle in a 1D box lead to increasingly well-separated energy levels? I know that the separation of energy between the levels is given by ΔE = (2n+1)h^2 / 8mL^2 which means that the higher the n, the greater the energy...

i am trying to understand the magnetocaloric effect from another point of view (besides thermodynamics ) , i know that under the influence of an external field , a zeeman splitting happens , and the electrons will have different levels of energy , those with + 1/2 spin will have a higher energy...

I remember this forum from years back as a good place to ask speculative science questions, so I figured I'd give you guys first dibs. Sorry if I put this thread in the wrong place. I'm doing some fantasy world-building, and I'm curious as to what the Great Lakes would look like at various...

So while watching Better Call Saul I asked myself, if you shielded yourself from radiation like Chuck, not only electromagnetic but all types as much as you could, say in your office, car, and home so most of your time is spent with significantly less tiny particles messing with your cells...

Okay so I just had another (silly) doubt Consider a hydrogen atom (1 proton in the nucleus and 1 1s electron) We know that the total energy of the hydrogen atom in its ground state is -13.6 eV And let's say in order to excite the electron to jump to n=2 the total energy should be -13.6/4=-3.4eV...

Homework Statement I'm reading some text on solid-state lasers and a passage that struck me was this: "The low-lying energy levels of the ion are determined by the forces acting on and between the electrons in unfilled shells. (The electrons in unfilled shells can be regarded as inert.)" If...

Hello, I wonder how the speed of interaction affects the energy levels in atoms. We know that electrons in atom are attracted to the protons in the nucleus through the electromagnetic force. Photon, the force carrier for the electromagnetic force, moves in empty space with the speed c (the...

If there was a bond in the 2p vs 3p subshell, which would be stronger? Taking into consideration that they are in the same group Thanks

Although I have not been thinking very much about actual physics for while now I suddenly got the urge to read a little bit about it and I decided to start by checking out the birth of quantum mechanics again. In the book quantum theory by Bohm in chapter 1 the ultra-violet catastrophe and its...

Homework Statement *This is not my whole problem, I am only stuck on how to interpret one part of the question. Put simply, I want to find the expression for the density of energy levels in a given energy band per unit volume (in some crystal structure). Say I have an infinitesimal interval of...

Homework Statement Find the energy levels of a spin ##s=\frac{3}{2}## particle whose Hamiltonian is given by: ##\hat{H}=\frac{a_1}{\hbar^2}(\hat{S}^2-\hat{S}_x^2-\hat{S}_y^2)-\frac{a_2}{\hbar}\hat{S}_z## where ##a_1## and ##a_2## are constants. Homework Equations In the ##\hat{S}_z## basis...

Homework Statement What are the causes of Global Sea Level Rise during the last century A. Thermal Expansion of the Oceans B. Melting of Glaciers C. Post Glacial Rebound D. A and B ans D It is possible to estimate Global Sea Level Rise using data from a hand-full of tide gauges. A true B...

Homework Statement Been looking but can't seem to find any comprehensive help on this. In the Hydrogen atom, what energy is associated with these electron energy transitions: a) N = infinity to N=2? b) N = infinity to N=3? c) N = 4 to N=2? d) N = 5 to N=6? I don't have any relevant formulas...

Homework Statement Attached problem Homework Equations Anti-derivatives, linear approx. F(a)=f(a)+F'(a)(x-a) The Attempt at a Solution I'm stuck on the first part, I think (w')^-1(1)= W which is 1. It seems too easy... and for part c I'm having trouble finding the equation for the line. I...

Homework Statement For large intensities, what is the maximum ratio of atoms in N1 compared with N3? I suppose this is just a bit of maths I'm struggling with, seems simple I just can't get it for whatever reason D: Working through previous question, I got to: N3= (Ip/Is) / ((Ip/Is) +1 ) N1...

Homework Statement a) Explain qualitatively why the energy required to remove one electron from the ground state of the helium atom is much larger than that in hydrogen, while for other states the hydrogenic value is quite a good approximation, e.g. the 1s2s levels in helium have energies very...

Dear all, I was wondering about the problem of calculating the probability that an electron will tunnel through a certain barrier (let's assume it is a constant value). Problem is that the initial and final energies of the electron are fixed and possesses a certain broadening (for example...

Hi everyone, So I'm currently in the middle of my summer holiday (waiting for A Level results) and I'm getting pretty bored of not knowing what to do. (I have contacted some charities for volunteer work but still waiting to hear, anyway that's beside the point) At A Level I studied Maths (Core...

Ive been struggling with this for days trying to make sense of a rpm vs torque chart I've seen recently. The chart states the engine load was measured 100% 70% 40% 0% and at 1000 2000 3000 4000 rpm. How is this done if using a chasis dyno? I attached the chart for reference. That's my...

We know that some genes produce mRNAs (and then proteins) and some other genes produces just ncRNAs (non-coding RNA) that play regulatory roles (yes, I know that some ncRNAs play other roles, but let’s forget about them now). I want to know a bit more about this regulatory processes. Does every...

I'm looking for a book to self-study this summer before my last course of Bachillerato (A Levels or High School in other countries). My performance in Mathematics has only improved and I've just been given the maximum mark this last term (10/10 or A+). This has motivated me a lot to keep...

Say we have a Quantum Dot with $$n=10^{26}m^{-3}$$ and radius $$R = 3nm$$ then this will give us of the order of 13 electrons. My question is how do you relate the number of electrons to the quantum numbers n and l in order to use the spherical Bessel function values? In class for 13 electrons...

Homework Statement Draw an energy level diagram for hydrogen (use the vertical direction for energy and separate the states horizontally by angular momentum l) Homework Equations I've got some fundamental misunderstandings with this one. I thought the energy levels of hydrogen were given by...

Homework Statement A 0.39 kg mass falls from a height of 2.9 m. If all of the energy of this mass could be converted to visible light of wavelength 5.5 × 10^−7 m, how many photons would be produced? The acceleration of gravity is 9.8 m/s^2 . Planck’s constant is 6.63 × 10^−34 J · s, and the...

Homework Statement A 0.39 kg mass falls from a height of 2.9 m. If all of the energy of this mass could be converted to visible light of wavelength 5.5 × 10^−7 m, how many photons would be produced? The acceleration of gravity is 9.8 m/s^2 . Planck’s constant is 6.63 × 10^−34 J · s, and the...

Dear Everyone, If we have a set of diatomic molecules consisting of a common element (F atom) and the other atoms belong to the same group; which are: BeF, MgF, CaF, SrF, and BaF. We want to study the electronic structure of these molecules by comparing their molecular electronic states. We...

See photo attachment! (question 1(b) and see answer on mark scheme underneath) How can three photons be emitted? Either the electron drops down from 3 to 1 and skips 2 emitting one big 12.1 eV photon OR it falls down in step emitting two photons 1.9eV and 10.2eV. How can it emit more energy...

Hi PFs whith atoms in the ground level |g> we can prepare them in the first excited energy level |e> by giving them the transition energy with a laser. if one photon is absorbed it will be in |e>. I read that to prepare a |e> + |g> state i can use a ##\pi/2## pulse with this same laser. What is...

As the atoms of a material are brought closer together to form the crystal lattice structure, there is an interaction between atoms, which will result in the electrons of a particular shell of an atom having slightly different energy levels from electrons in the same orbit of an adjoining atom...

Hello Biology folks! So here is my problem: I have done my bloodwork(full analisis),the results are all satisfying,except my AST and ALT levels. My levels: AST: 77 ALT: 48 Note:I am a almost 17 year old male,73 kg,183cm high. I haven`t drunk any alchol since new years eve and before that not...

Homework Statement Consider three electrons in three different orbital levels n, m and p. We assume that there is one electron in each orbital level. How many states are then possible? Homework Equations Equations for constructing symmetric and asymmetric wavefunctions: Symmetric under pair...

Hello, I was trying to solve a problem in my course book, and I noticed I don't really understand energy levels completely. My ignorance covers more than one specific problem, so I figured I'd ask a general question, rather than post the problem. The Rydberg formula: ##...

Why do electrons further away from the nucleus have more energy? When my book mentions energy in different orbitals, is it talking about potential energy? If it is, I'm confused because potential energy is inversely related to distance, so if distance increases, the potential energy decreases.

Homework Statement I must find the average number of energy levels of quantum harmonic oscillator at temperature T, and the answer is given as I must use Boltzmann distribution and the sum of geometric progression. For finding the average value I must use the equation <F>=trace(F*rho)...

Homework Statement With the atomic clock a second is defined as the time it takes for EM radiation to oscillate 9192631770 times, which equals the energy gap between two energy levels of a caesium-133 atom. Note: it's a translation and the term used with the oscillation is "oscillation periods"...