Levels Definition and 471 Threads

  1. L

    Molecular hydrogen excitation levels

    Hi, I am looking for electronic excitation levels of molecular hydrogen like attached table. but there are only a few electronic states, i need near-threshold energy levels. where can i find all levels? thanks for attention http://imgim.com/5648inciz1637947.jpg
  2. K

    Calculating Energy Levels and Wavelengths in the Hydrogen Atom

    Homework Statement In the hydrogen atom, the electron jumps from the n = 1 level to the n = 4 level. a. During this transition from n = 1 to n = 4, is a photon emitted or absorbed? b. What is the change in energy of the electron? c. State the transition in words. d. What is the wavelength...
  3. D

    How do we use this to solve for the spacing between levels?

    Homework Statement So I'm stuck on part (ii) where we have to solve the rotational energy levels. Problem: http://screencast.com/t/9rZStJdG3wJ The answer is ii) 0, 3.84 cm-1, 11.52 cm-1 Homework Equations Equations: http://screencast.com/t/ubFEheGBz The Attempt at a Solution...
  4. F

    High(er) Levels Maths problem books?

    Hello Guys, I am new to this forum, but have recently fallen in love with physics and maths. I am an international baccalaureate student, who studies maths, and was wondering whether any of you could suggest any books to help with a certain kind of problem. At the end of our papers...
  5. nukeman

    Can someone me understand pH levels (Meaning mainly for certain molecule)

    Hey, I am trying to figure out some research for a department at school, and need some chemistry info. Basically, I am comparing D2O (Heavy water) HDO (Semiheavy water) and H2O (Light water) NOW... each of them have different pH levels. What does that mean that they each have...
  6. J

    Energy Levels According To Second-Order Perturbation Theory

    Homework Statement If E1≠E2≠E3, what are the new energy levels according to the second-order perturbation theory? Homework Equations H' = α(0 1 0) (1 0 1) (0 1 0) ψ1= (1) (0) (0) ψ2= (0)...
  7. C

    About fermi levels in extrensic semiconductors.

    Why does the Fermi level level drop with increase in temperature for a n type semiconductor.? What's the basic idea behind Fermi level? How does it get affected by temprature?
  8. L

    Atomic Energy Levels - Calculating the Minimum Energy of Light Emitted

    Homework Statement Determine the longest wavelength of light emitted from this atom. Homework Equations \lambda=\frac{hc}{E} The Attempt at a Solution I calculated the lowest energy of the light emitted: E_{min}=2.1(eV) Then the longest wavelength would be...
  9. C

    Registration fees for A levels as private candidate?

    All right, I'm planning to sit A level exams this January, I've been persistently studying the subjects but I'm not sure what the fees are. I'm applying rather late because I've found out where I can sit the exams by coincidence when I was losing hope of ever finding any information on the...
  10. L

    Fermi Distribution of Energy Levels

    Based on Fermi distribution, if there are two electron energy levels with occupation possibility of ¼ and ¾, respectively, calculate energy difference between these two levels.
  11. H

    Change in Potential Energy levels of a body in Gravitational field.

    Homework Statement Now , I Will Begin by stating the calculation and i will post the query at the end. so here we begin, we know that If W is the work done by a conservative force, potential energy change is given by: ΔW= - ΔU ...(1) ie when work done by conservative force is positive...
  12. P

    Which bacteria infect our food? What are their growth rates? Harmful levels?

    I'm curious about food preservation. Which are the most common dangerous bacteria? How quickly do they grow? What sort of conditions? And how many must be present to pose a threat to a human? Also, how do they survive the stomach? Do they infect via the mouth or esophagus?
  13. W

    A very basic question about the the origin of quantum levels

    Does anyone know why quantum states exist? In other words, is there an explanation for why the universe is built from discrete levels vs. some other system? I've scanned over numerous books on quantum mechanics and the history of quantum mechanics but I can never find a layman's answer to this...
  14. D

    Application with 3 A levels only?

    I'm applying to Cambridge Maths. Will I be disadvantaged if I only take 3 A levels and no additional AS? I have no GCSE equivalent as well.
  15. B

    Photons coming from atoms, when electron changes levels

    Today I did the usual thinking, watched some courses online etc. and found out(or rather reminded myself) that the EM waves can be produced only when a charge oscillates.(or that's what the professor at Yale said) But then I remembered LED diodes, and their ability to emit light. Electron...
  16. B

    Photons coming from atoms, when electron changes levels

    Today I did the usual thinking, watched some courses online etc. and found out(or rather reminded myself) that the EM waves can be produced only when a charge oscillates.(or that's what the professor at Yale said) But then I remembered LED diodes, and their ability to emit light. Electron goes...
  17. R

    What are atomic energy levels?

    what are atomic energy levels? are they different in principle to electron energy levels? how to visualize atomic energy levels in any substance (solid, liquid and gas) I have read that during the formation of bose einstein condensate all the atoms comes to ground level from high energy levels...
  18. T

    How much are sea levels expected to rise by the year 2100?

    Will they rise slow and gradual allowing for a somewhat seamless transition of population to higher ground, or will there one day be a large storm that will inundate an area permanently? What are the implications for the gulf coast, South Florida, and the East Coast? How will vital...
  19. S

    How does electricity travel so quickly?

    HI! i only know about the basics of current and electricity , but, i wanted to ask this.. the drift velocity in electrons is approx 10^-4 and thermal velocity is 10^6 m/s , which is not very large compared to the length of wires connecting power stations and homes , but still we get...
  20. C

    Energy levels of exponential potential

    Homework Statement Find the eigenfunctions (with angular momentum 0) and the estimation of the 3 first energy levels (given g and a) of a particle in a exponential potential such as V = -ge-r/a Homework Equations Time independent Schrodinger equation (SE)The Attempt at a Solution Did a...
  21. R

    Corresponding Energy Levels for Normalised Eigenfunctions

    Homework Statement Particle of mass m in a 1D infinite square well is confined between 0 ≤ x ≤ a Given that the normalised energy eigenfunction of the system is: Un(x) = (\frac{2}{a})\frac{1}{2} sin (\frac{nx\pi}{a}) where n = 1, 2, 3... what are the corresponding energy levels...
  22. P

    Understanding Nd:YAG Laser Energy Levels

    Hey guys, A simplified diagram for the energy levels involved in Nd:YAG laser can be found here: http://upload.wikimedia.org/wikipedia/commons/6/69/YAG2.svg Two (short) questions: 1. Selection Rules The lasing transition happens between ^{4}F_{3/2} and ^{4}I_{11/2}. In the process J (of the...
  23. L

    Calculating Rotational Energy Levels for a Caroussel: How Do I Proceed?

    Hello forum members... I have a problem in calculating the energy of rotational levels. Kindly help me...The question goes like this: A Caroussel(merry-go-round) of diameter 20 m and weight 1 ton( =1000 kg that is evenly distributed on the discs) rotates 10 times per minute. Calculate the...
  24. B

    Rate of change of quantum levels (emission spectra) at 333 cm sized atoms

    Hi there, my comparatively ignorant mind is wondering, When an atomic transmutation occurs all of the quantum levels of the new atom also change 1) what is the actual rate of this change? would a nonplayer "observer photon" passing near the suddenly different element note the quantum level...
  25. L

    Degeneracy of hydrogen energy levels

    Consider a universe where the intrinsic spin of the electron is S = 5/2, but all other parameters and Rules of Quantum Mechanics are the same. Find the degeneracy of the n=1 and n=2 levels of hydrogen. My understanding is that electrons in an atom have 4 quantum numbers n,l,ml,ms, and different...
  26. S

    Higgs Boson and confidence levels

    What is the current state of things? Are they fairly confident that the Higgs exist despite more data being needed for the 5-sigma confidence level? Could it still (realistically) turn out to not exist?
  27. J

    Energy quantization and energy levels

    Hello ! I had my fair share of quantum mechanics already :) But today I was wondering something, kind of odd I thought of this so late ... But do continuous energy levels really excist or is it just an approximation. I am asking this cause by my understanding energy is quantized, so...
  28. N

    Energy of atoms in different levels

    Homework Statement In a set of experiments on a hypothetical one-electron atm, you measure the wavelengths of photons emitted as electrons return to the ground state (n=1), as shown in the energy level diagram. You also observe that it takes 17.50 eV to ionise this atom. Diagram shows...
  29. M

    Comparing Vibration Levels of PVC & Nylon Pipes

    Homework Statement i want to check out which material of pipe vibration level higher . comparison between pvc pipe and nylon pipe. nylon pipe is more soft and flexible than pvc pipe. which one vibration more ? Homework Equations The Attempt at a Solution
  30. H

    Tricky Buoyancy Problem Involving Water Levels

    I'm trying to work through the below problem but it is a bit tricky and I would love any helpful tips: A boat with a lead block on it is sitting in a pool. On the side of the boat is a red line right at the water level. On the side of the pool is a blue line right at the water level. The...
  31. B

    Should I take Further Maths and/or Chemistry A levels?

    Hello, I am new to these forums. I am in Year 10 and have decided to take Physics and Maths at A level. However, I need to choose 2 more A levels and have considered Further Maths and Chemistry. I would like to take Chemistry because I love science! But I'm worried there will be too much...
  32. Q

    A problem about levels of confidence

    It is known that a process occurs with a frequency of 10 events per second and a second process with a frequency of 12 per second. Consider the two situations: 1. It is possible to repeat N times the experiment, that consists in counting the processes, over a period of 10 seconds. 2. It is...
  33. I

    Intel Pay Grade Levels: Yrs Exp Range

    Do you know the corresponding years of experience range for Intel pay grade level 7, 8 , 9
  34. binbagsss

    Deriving Energy Levels of a Particle in a Box

    Deduce the formula giving the energy levels in terms of n for a free particle in a box of length l, using the fact that only stationary waves can be occupied by the particle. - considering stationary waves, λ = 2l/n. (1) 1) Using E=hv/λ= hvn (2) And P = h/λ, v = h/m*λ, v = hn/2ml (3)...
  35. Q

    Why Does Electron Energy Have Negative Values?

    hi, why are the energy levels of electrons in say a hydrogen atom -13.6ev, -3.4 eV etc ? i thought energy is always positive? what does the negative mean? thanks!
  36. G

    Missing something pretty simple in counting energy levels?

    Homework Statement Determine the no. of energy levels with different values of total spin for a system of N particles with spin 1/2 The Attempt at a Solution Let f be the no. ways to get a z projection of spin, then f(\sigma )=Binomial(N,\frac{1}{2}N + \sigma) Where Binomial(a,b) is a chose b...
  37. G

    Exchange splitting of energy levels of a system?

    Exchange splitting of energy levels of a system?? Hey guys, I was just reading my QM book and came across this; Homework Statement Determine the exchange splitting of energy levels of a system of two electrons, regarding the interaction of the two electrons are a perturbation. My...
  38. C

    Energy levels hydrogenic atoms

    I don't get why for hydrogenic atoms the 2s and 2p orbitals have the same energy. i do get it mathematically, but I am thinking that the fact that there are angular nodes in 2p and not in 2s MUST affect the energy!
  39. L

    Discrepancy between oxygen and carbon-dioxide levels

    Does anyone have explanation, or can point me to papers explaining this thread title? Personally, I did some reading through years, but I could never find an answer to this question. In short, here is what I learned so far: Oxygen: - in free form, is a product of photosynthesis of...
  40. C

    Is photon emission possible without electrons changing energy levels?

    Does molecular vibrational transition and consequent emission of infrared radiation involve electrons changing energy level? In wikipedia, about vibronic transitions it says "Most processes leading to the absorption and emission of visible light, are due to vibronic transitions. This may be...
  41. J

    Energy levels and quantum state

    Would anyone be able to explain s,p,d,f in detail without using complex math? Also quantum states such a m,l etc. or link me to a site/paper that does? thanks
  42. F

    Rare-earth energy levels from LS coupling

    Hey all, Is there a way to rank the energy levels of a rare-earth ion in order of increasing energy just from the spectroscopic terms? Nd3+ has an electron configuration of [Xe]4f^3, which produces energy levels such as 4I, 4F, 2H, 4S, 2G, 4G, 2D, etc from the electrostatic interaction...
  43. binbagsss

    Quick Uncertainty Problem - atom energy levels

    Two quick problems, not sure whether the 2 are related or not: 1) The question is: A sodium atom in one of the states laveled 'lowest excited lvels' remains in that state, on average, for 1.6 x 10^-8 s before it makes a transition to the ground level, emitting a photon with wavelength...
  44. jbrussell93

    Schrodinger's Cat: Conscious Observer & Levels of Organization

    My first question is pertaining to Schrodinger's Cat (i know... I am still trying to grasp these concepts). So, wouldn't it make sense that the cat would be a conscious observer therefore causing wave function collapse in the first place? My other question is just a general question about...
  45. N

    Given a potential, qualitatively deducing the energy levels?

    Given the basic result that the harmonic potential well has the energy levels it has, are there ways to convincingly deduce the qualitative properties of the energy levels given a certain potential well? Take for example a Morse potential, is there a way to deduce (vague if need be, exact if...
  46. P

    Interfacing question of different voltage levels

    Hi all, i have this small interfacing problem somebody please suggest me how to resolve this problem. i have two hardware boards say unit 1 and unit 2. The Unit 1 has 48 digital inputs and outputs configurable through software as either input/ouptut but they are ttl level i.e 5V logic. i have...
  47. D

    Molecular Orbital energy levels

    Hi everyone I'm currently studying the MO theory and ran into some trouble understanding orbital energy levels. As I have previously read, σ bonds are stronger than ∏ bonds, therefore are lower in orbital energy. However, from the MO theory, the σ2p orbital is actually higher in energy than...
  48. C

    What are vibrational levels and energy states?

    I know that UV-Vis spectroscopy is based on the principle of electrons jumping to higher energy states but I just read that each energy state has a number of "vibrational energy levels" inside it. Heres a diagram: I'm confused now, what is a vibrational energy level and what is an energy...
  49. D

    3D Schrodinger Equation of a Wire for Energy Levels - Quantum Physics

    Homework Statement Given a wire with length a and square base b x b (where a >> b), show that the first 1700 (approximately) levels of the electron in the wire are identical for the one dimensional box, when a = 1m and b = 1mm. Homework Equations I know that the allowed energies of...
  50. G

    Energy levels in Hydrogen - derivation

    Homework Statement We know that: E=<\psi|H|\psi> where H=-\frac{\hbar^2}{2m} \nabla^2 - \frac{Ze^2}{4\pi\epsilon_0 r} and \psi=R(r)Y(\theta, \phi) with R(r)=\frac{1}{\sqrt{(2n)!}}(\frac{2Z}{na_0})^{3/2}\left(\frac{2Zr}{na_0}\right)^{n-1}e^{-Zr/na_0} If I want to find the energy, do...
Back
Top