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Home Q & A Board Science-Related Homework Help Physics
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mireiajordan mireiajordan
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6 years ago
In his calculations, Bohr came across a number now called the Bohr radius. This number is 5.29 X 10-11 m and is
  A. The maximum radius of the hydrogen atom.
  B. The minimum radius of the hydrogen atom.
  C. The average radius of the hydrogen atom.
  D. The minimum radius of atoms of all elements.
  E. The maximum radius of atoms of all elements.


[Ques. 2] The planetary model of the atom was fundamentally flawed. It failed theoretically because
 
A. a perfectly circular orbit would violate the laws of gravitation.
  B. electrostatic attraction would not be sufficient to keep the electron/nucleus in a bound state.
  C. it predicted positive and negative charge equally distributed throughout the atom.
  D. it was well established experimentally that accelerating electrons emit electromagnetic radiation.
  E. it did not provide for the existence of neutrons.



[Ques. 3] What did Rutherford's famous scattering experiment help to prove in his day?
 
A. The nucleus of an atom is positively charged.
  B. The nucleus of an atom takes up a large portion of the space in an atom.
  C. The scattering with the gold foil could either be due to a single interaction with a nucleus or multiple interactions with electrons.
  D. Alpha particles are neutral and massive.
  E. Thomson's model was essentially correct.



[Ques. 4] How did Thomson measure the charge to mass ratio of the electron?
 
A. He shot helium nuclei into gold foil to measure the nuclei scattering against electrons within.
  B. He passed cathode rays through a magnetic field and measured the deflection.
  C. He suspended a drop of oil between electrodes to measure the electric field from the electrons.
  D. He measured very precisely a known quantity of hydrogen atoms and calculated the reduced mass ratio within each atom.



[Ques. 5] What is the bremsstrahlung process?
 
A. The emission of a photon from an electron being accelerated by a nucleus
  B. The emission of an electron from a metal when light is shined on it
  C. Thermal excitation of photons in a substance
  D. The emission of an electron from an inner electron shell and the resulting photon when an electron drops from an outer shell to take its place
  E. Converting power-producing nuclear material to weapons grade



[Ques. 6] An electron approaches a positron. They annihilate and produce two photons, which fly off at the speed of light in opposite directions. Analyze the situation using relativistic momentum and energy and choose the false statement below.
 
A. If the resulting photons have the same wavelength, then the electron and positron must have had equal momenta.
  B. The kinetic energies of the positron and electron determine the frequency of the gamma rays produced in the annihilation.
  C. The rest energies of the positron and electron determine the frequency of the gamma rays produced in the annihilation.
  D. The photons can have the same wavelength, but it is not necessary.
  E. There can be two photons produced (as in the above example), but only one photon can is produced in some cases.



[Ques. 7] Which of the following are assumed when analyzing photons involved in Compton scattering?
 
A. Momentum, but not energy, is conserved when the photon scatters from an electron.
  B. The photon always recoils with significant energy lost to the electron.
  C. The photon behaves like a wave and diffracts at an angle from the electron.
  D. Scattering from tightly bound electrons always produces the photons with greatest wavelength change.
  E. Energy and momentum are treated relativistically in the scattering.



[Ques. 8] Which of the following statements about blackbody radiation is NOT correct?
 
A. The wavelength of peak relative intensity emitted from a blackbody depends on 1/T, the temperature of the blackbody.
  B. The power per unit area given by blackbody radiation depends on T4.
  C. The classical theory of intensity vs. wavelength, the Rayleigh-Jeans formula, of blackbody radiation is only correct at large wavelengths.
  D. Planck's radiation law for intensity vs. wavelength of blackbody radiation depends on and T4.



[Ques. 9] Which of the following statements is correct about the experiment that first measured the charge of the electron?
 
A. The oil drop is suspended because there are no forces acting on the drop
  B. The important result was that Coulomb attraction made all of the oil drops the same mass, regardless of type of oil
  C. The mass of the drop was determined by measuring its terminal velocity
  D. The value for electron charge had an experimental error of about 35
  E. Light hitting the oil drops manipulated their movement in a way to create an interference pattern.



[Ques. 10] When you interchange your emitter for one with a smaller work function, you measure
 
A. An increased current
  B. A decrease in the necessary stopping voltage
  C. An increase in the necessary stopping voltage
  D. No change in either current or stopping voltage
  E. Either a or c. You cannot determine which from the information given.
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sneeedysneeedy
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6 years ago
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mireiajordan Author
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#2
6 years ago
So that's it? I get an expert answer then we move on with our lives? Not too bad Slight Smile
wrote...
#3
6 years ago
we do it for the love of comments
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