Levels Definition and 471 Threads

Hello I am sitting in my home and I'm using 2 phone apps to measure my EMF levels (they both got the same number). I measured it about every 10 minutes. This is what I got 1)~46uT 2)`~189uT 3)~187uT 4)~48uT 5)~187uT 6)~50uT 7)~50uT It never reached under 40uT and I would say this morning, on...

From what I read I see that for example a radioactive nucleus is a nucleus in an excited state and when it transitions back to it's stable state (changes from one element to another due to radioactive decay) one of the ways this happens is that the nucleus emits a energetic photon with a...

I'm considering a hydrogen atom placed in an infinite potential on one side of the nucleus, i.e. ##V(x) = +\infty## for ##x < 0##. I require the wavefunctions to be odd in order to satisfy the boundry condition at ##x=0##. By parity of the spherical harmonics only states with ##l## odd are...

Background: This is going to be a shorter thread compared to the last thread I made, which was quite long. It is related to a question I posted on MSE/mathoverflow few weeks ago (https://math.stackexchange.com/questions/3403361/eventual-writability-general). The linked thread also contains the...

Dear PF, I hope I've formulated my question understandable enough. Thank you for your time, Garli

I would like to get some information on this topic. It is not discussed in many places, so if any members here know about it, i would be interested in a brief explanation. Or any books or online documents where it is discussed. D is the "invariant propagation function" or the "propagator". I...

Hello, I'm doing some refreshers before going back to school. Stat mech is my shakiest and I'd appreciate some help on this problem. I know that for a single particle, the partition function will be $$Z = 1 + 2e^{-\beta\Delta} + 2e^{-4\beta\Delta}$$ and so its internal energy is $$\frac{1}{Z}...

ESL: Since valuable discussions are being made and then threads closed, here is an input: Melting ice to liquid water, will gather around equator because of gravity @lomidrevo

Summary: Does an atom in an excited state have a higher mass than when in its ground state? Summary: Does an atom in an excited state have a higher mass than when in its ground state? Does an atom in an excited state have a higher mass than when in its ground state?

I found one answer somewhere else in the internet, It specified there that atoms cannot have rotational and vibrational energies since they don't have a point on them that will allow the atom to be rotated or vibrated. However , that answer did not suffice so I ask the same question here.

How much is too much gravity for life as we know it to exist on a body too small to become a star? At approximately what multiple of 1g would life as we know it be impossible because of the direct effects of gravity? What about secondary factors--e.g. how the higher gravity would affect the...

Here is the BBC article, I've read today. Conclusion from the original study: This sounds really alarming to me.

Hi All. For the above energy level diagram, why do the energy levels spacings proceed to get smaller and smaller as the excitation energy increases?

These are the experimental results for the energy levels of Samarium-154: From 0+ to 8+ I recognize rotational energy: $$E = \frac{l(l+1)\hbar^2}{2I}$$ But from there on I do not know how to justify the rest. I have been reading that we sometimes get energy diagrams like above for even-even...

Greetings, I have troubles at getting a good intuition on how acceptor energy levels are formed above the valence band in p-doped semiconductors. Ashcroft describes the following scenario: With n-type doping, the added impurity can be modeled as a positive ion with an additional electron. The...

Hello soon to be saviors, 😊I have two really simple questions that I have already answered but the teacher wants more info. I am really stumped and I am not looking for the answers so much as an explanation on how to better answer the questions. I will copy and paste the problems and my answers...

If my inside relative humidity level is 50% at 73 F, and my outside relative humidity level is 97% at 36 F, how can I tell if I open my door, whether I will lose inside humidity into the atmosphere? The real life scenario is that my wife complained that the humidity was too low in the house...

I have been studying about the physiology of hunger. I have studied about the hormones that are involved in the process of hunger, like ghrelin, leptin, pancreatic polypeptide, cholecystokinin, cholecystokinin (CCK) and the neurons like AgRP, POMC and neuropeptide Y (NPY) etc. I understand...

Homework Statement I'm having trouble understanding the existence of valence shells. I understood that valence shell is the last energy level for the electrons to populate around an atom. But, according to Bohr model , an atom can have infinite energy levels , so I don't understand: How can...

Homework Statement Homework Equations The Attempt at a Solution I understand the equation, and I understand the concept. My question is this: What is the best way to go about solving this problem? My line of reasoning concludes that the fourth lowest energy level is E211. However, the...

Hi I'm doing A levels now and I'm planning to go to University of Toronto next year September for engineering science, my question is what are the grades needed for my AS and A2 level to get into engineering science? My trial results are A in Chemistry and Math, A- in physics and B in biology.

I've noticed that in the Shell Model of the nucleus, the order of the energy levels is 1s, 1p3/2, 1p1/2, etc. While in the atomic energy levels it goes 1S 2S 2P, ... But they still take the same amount of particles for each level in both the atomic and nucleus. Am I missing something here? Or...

https://www.ncbi.nlm.nih.gov/m/pubmed/22552705/ Replicating past findings, no significant correlations between T and desire in men were apparent, but these analyses showed that the null association remained even when psychological and confound variables were controlled. Men showed higher desire...

Which are main absorption modes of matter for gamma rays under about 500 MeV? And how strong is the absorption? For low energies (under 20 MeV) the mechanisms are: 1) Photoelectric absorption - all energies from eV range onwards 2) Compton scattering - all energies enough to displace the...

[Mentors' note: Moved from the technical forums, so no template] Hi, I have to find energy levels of an electron in a cylindrical shape. I know how to derive the formula below: However, I'm not sure which zero value and what intger p I need to use in order to find the lowest energy. If these...

When I read about carbon sinks and the production of CO2, I am puzzled by the trust we have in carbon dating. If I understand correctly, C14 is produced by cosmic rays and nitrogen and is considered a very steady process thus carbon dating is trusted. But if C14 is brought into biological...

Homework Statement a) Draw a diagram of energy levels to explain the spectrum of lines of the hydrogen atom b) Indicate, for each photon, that its region can be emitted to the electromagnetic spectrum. c) Compare, in a graph, the energies of the orbital of the hydrogen atom with the energies of...

Hi, I have a very basic statistics homework question, and I have given it a go, but I just wanted to know if I had approached it correctly: QUESTION A shop adjusts its staffing levels using a model of customer demand through the week in the ratio of: 0.22(Mon); 0.14(Tue); 0.16(Wed); 0.18(Thu)...

Homework Statement If a system comprised only of two electrons was physically possible (such as positronium but with two electrons), what would its energy levels be and how would they relate to the energy levels of Helium? Homework Equations ##E_{Helium} = E_{n1}+E_{n2}=-\frac{\mu Z^2...

Homework Statement Consider the NaCl molecule, in which the atomic weights of Na and Cl are 23 and 37, respectively. The internuclear separation is 0.236 nm, and the ”spring constant” for vibrations is k = Mred ω^2 = 1 × 10^9 J/m^2 . Calculate the energy difference between adjacent vibrational...

I was wondering about the filament colors in a plasma ball that I have got. The main part of each filament is blue, but its end part is pink. Possibly the gas is 95% neon and 5% xenon, the pink part is light emitted by neon, and blue part light emitted by xenon. Using a hand spectroscope I...

Since it seems unlikely (to me) that current approaches will very rapidly stop the increase in CO2 levels driving climate change, alternative approaches involving removing CO2 from the atmosphere are being explored. Here is a link to a Science mag news article about using plantations to do...

If one considers the quantized levels of E, for the solutions to the Schrödinger eqn,, then I am wondering: what are the lowest possible energies that can occur for the Schrödinger eqn? I take the highest possible energy is at the classical limit, but is the zero-point energy the absolute...

Homework Statement PROBLEM STATEMENT: Show that with an n × n pixel grid, where each pixel can take on m intensity levels, we can approximate n × n ×(m – 1) + 1 overall intensity levels. TEXTBOOK'S SOLUTION TO THE PROBLEM: Since the n ×n pixels can be set to a non-zero intensity value one...

Why does max tegmark's and brian greene's levels of multiverses consider as the highest level the mathematical multiverse hypothesis if other authors like David Lewis consider that there could be also universes non described by maths? Why does it stop at level iv (mathematical universes...

Homework Statement If the first two energy eigenfunctions are ## \psi _0(x) = (\frac {1}{\sqrt \pi a})^ \frac{1}{2} e^\frac{-x^2}{2a^2} ##, ## \psi _1(x) = (\frac {1}{2\sqrt \pi a})^ \frac{1}{2}\frac{2x}{a} e^\frac{-x^2}{2a^2} ## Homework EquationsThe Attempt at a Solution Would it then be...

Please can someone explain me how high levels of ultrasound can be created in Air? Should we consider the Ultrasound or we should concentrate only on sound level in Air as frequency ultrasound have no effect on sound level?

Homework Statement When an electron in a hydrogen atom makes a transiton between two levels with prinicipal quantum numbers n1 and n2, light is emitted with wavelength of 658.1 nm. If we assume that the energy levels of the atom are in agreement with the Bohr model, what are n1 and n2...

The question I have been given: Draw the dominant forms of each of the compounds below and state which, if any, would be expected to extract from aqueous solution into hexane at (a) pH 12 and (b) pH 2. CH3CH2COOH CH3CH2NH2 CH3CH2CH2OH H2NCH2CH2COOH From my understanding, I can tell what the...

Homework Statement 1D Potential V(x) = mw^2x^2/2, part of a harmonic oscillator. Suppose that the spring can only be stretched, so that the potential becomes V=infinity for x<0. What are the energy levels of this system? Homework EquationsThe Attempt at a Solution I argued my way though this...

I'm trying to understand cyclotron resonance measurements of electron effective mass in intrinsic silicon. I need to understand the theory used to make the computations of effective mass in non-parabolic bands. A basic introduction to the cyclotron technique is here, but only for parabolic...

Hi.. I have a 40 volt (2.5Ah) , Lithium Ion battery. I need to use this battery for 20V application as well as 40V application. How to make an automatic voltage level chooser module for respective application?

Homework Statement Hi guys, I was just wondering if anybody could help me with the below question Homework EquationsThe Attempt at a Solution Radial Total load = 3.2 /_-36.87deg + 2.3 /_ 53.13deg =(2.56 - j1.92) +(1.38 +j1.84) = (3.94 -j0.08)...

In the 'Particle in a box' system, with the well being extremely narrow, why does the particle path have to follow certain energy levels compared to the classical system? Thanks in advance.

Hey, I just had a quick question about using hamiltonians to determine energy levels. I know that the eigenvalue of the hamiltonian applied to an eigenket is an energy level. H |a> = E |a> But my question is if I am given an equation for a specific Hamiltonian: H = (something arbitrary) And...

Suppose we have some model for some system, and that model has given us a sequence \mathcal{E}_1,\mathcal{E}_2,\mathcal{E}_3,\ldots, whose values are interpreted as the energy levels of the system. Denoting the energy levels slightly redundantly for future modification soon below, we state that...

I have been reading about Landau levels for a two-dimensional system of charged particles in a perpendicular magnetic field and I have trouble understanding why there is degeneracy in the system. Let me provide some background to my problem. In the presence of a magnetic field, the momentum of a...

Homework Statement A system has three non-degenerate energy levels with energies 0, ε, and 2ε. a) Calculate the entropy of the system if the three levels are populated by two distinguishable particles such that the total energy is U=2ε. b) Calculate the entropy of the system if the three...

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 =...