physics

posted by .

5)a. Electrons accelerated by a potential difference of 12.23 V pass through a gas of hydrogen atoms at room temperature. Calculate the wavelength of light emitted with the longest possible wavelength.
b. Calculate the wavelength of light emitted with the shortest possible wavelength

  • physics -

    Energy= 13.6*(1/n^2-1/1^2) which is the energy absorbed in a ground state to n state.
    12.23>13.6*(1/n^2-1) or
    12.23>13.6/n^2 - 13.6
    -13.6/n^2 > -1.11
    n^2< 12.34 or max n is 3

    Energy= 13.6(1/9-1)=12.08 eV

    Now from this, you can calculate max wavelength...

    Energy= hf= hc/lambda compute lambda (remember to change eV to joules).



    Energy= hf= hc/lambda

    lambda=hc/13.2 * n^2)

  • physics -

    The elctrons have an energy of 12.23 eV. The ionization energy of hydrogen is 13.6 eV. So, the electron beam will create ionized hydrogen as well as hydrogen in excited states.

    The shortest wavelength photons are emitted when an 12.23 eV electron from the beam is captured by an ionized hydrogen atom (that atom would then be ionized by an earlier collision with an electron from the beam) and bound in the ground state. The energy of the photon is then 12.23 eV + 13.6 eV = 25.83 eV which corresponds to a wavelength of 48 nm.

    There is no upper limit on the wavelength of the photon that can be emitted. When an electron from the beam collides with an hydrogen atom, the bound electron can be kicked out at any energy. These elctrons can be captured by protons at arbitrary high quantum number n. This means that the emitted photon can have arbitrary low energies.

    Also, the electrons in the gas will interact with the hydrogen atoms and this will cause emission of photons at arbitrary low energies.

  • physics: Correction -

    Correction: 12.23 eV is less than the ioniztion energy. So, it is abound state problem as explained by Bobpursley

  • physics -

    Hello Bobpursley
    I don't follow your steps. It is asked about longest & shortest possible wavelengths.Can you please explain?Thanks

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. *physics*

    Electrons accelerated by a potential difference of 12.87 V pass through a gas of hydrogen atoms at room temperature. Calculate the wavelength of light emitted with the longest possible wavelength. I don't know what equation to use. …
  2. Atomic physics

    5)a. Electrons accelerated by a potential difference of 12.23 V pass through a gas of hydrogen atoms at room temperature. Calculate the wavelength of light emitted with the longest possible wavelength. b. Calculate the wavelength of …
  3. Chemistry

    Calculate the wavelength of light emitted when each of the following transitions occur in the hydrogen atom. (a) n = 5 n = 4 _________nm (b) n = 5 n = 3 _____________ nm (c) n = 5 n = 2 __________ nm Calculate the maximum wavelength …
  4. Chemistry

    When an electron makes a transition from the n=3 to the n=2 hydrogen atom bohr orbit, the energy difference between these two orbits (3.0x10^-19 J) is given off in a photon of light. The relationship ... between the energy of a photon …
  5. physics

    b. If you are cruising down the road at 50 mph and a policeman with a radar gun (wavelength 1 cm) reflects radar light off your bumper, what wavelength of radar light does he get back?
  6. physics

    A tungsten target is struck by electrons that have been accelerated from rest through a 24.5-kV potential difference. Find the shortest wavelength of the radiation emitted. (in nm)
  7. Physics

    A tungsten target is struck by electrons that have been accelerated from rest through a 38.9-kV potential difference. Find the shortest wavelength of the radiation emitted.
  8. Physics

    A metal surface is struck with light of wavelength 430 nm releasing a stream of electrons.  If the 430 nm light is replaced by 380 nm light of the same intensity, what is the result?
  9. Physics

    Rank in order the following according to their speeds, from fastest (1) to slowest (5): (i) 425-nm-wavelength light through a pane of glass, (ii) 500-nm-wavelength light through air, (iii) 540-nm-wavelength light through water, (iv) …
  10. Chemistry

    An electron is excited from the n=1 ground state to the n=3 state in a hydrogen atom. Which of the following statements are true?

More Similar Questions