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| 1 | |
Compute the energy of a photon of a blue light l=450 nm), in joules and in eV. |
| | A) | 2.98 x 10-40 J = 1.86 x 10-21 eV |
| | B) | 1.47 x 10-27 J = 9.18 neV |
| | C) | 9.90 x 10-19 J = 6.18 x 10-30 eV |
| | D) | 4.41 x 10-49 J = 2.76 eV |
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| 2 | |
What is the wavelength of light in which the photons have an energy of 600 eV? |
| | A) | 6.89 x 10-18 |
| | B) | 2.07 nm |
| | C) | 484 Mm |
| | D) | 2.07µm |
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| 3 | |
With what speed will the fastest photoelectrons be emitted from a surface whose threshold wavelength is 600 nm, when the surface is illuminated with light of wavelength 4 x 10 -7m? |
| | A) | 1.1 x 106 m/s |
| | B) | 6.0 x 105 m/s |
| | C) | 8.6 x 105 m/s |
| | D) | 4.2 x 105 m/s |
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| 4 | |
Electrons with a maximum KE of 3.00 eV are ejected from a metal surface by ultraviolet radiation of wavelength 150 nm. Determine the work function of the metal, the threshold wavelength of the metal, and the retarding potential difference required to stop the emission of electrons. |
| | A) | (a) 5.27 eV, (b) 235 nm, (c) 3.00 V |
| | B) | (a) 8.27 eV, (b) 3.77 x 10-26 m, (c) 5.27 V |
| | C) | (a) 11.27 eV, (b) 235 µm, (c) 8.27 V |
| | D) | (a) 7.41 eV, (b) 4.25 Mm, (c) 2.27 V |
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| 5 | |
One spectral line in the hydrogen spectrum has a wavelength of 821 nm. What is the energy difference between the two states that gives rise to this line? |
| | A) | 1.51 eV |
| | B) | 2.42 x 10-19 eV |
| | C) | 1.51 keV |
| | D) | 1.02 MeV |
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| 6 | |
What are the energies of the two longest-wavelength lines in the Paschen series for hydrogen? What are the corresponding wavelengths? Give your answers to two significant figures. |
| | A) | (a) 1.5 eV and 5.3 x 10-5 m, (b) 1.5 eV and 7.7 x 105 m |
| | B) | (a) 0.66 eV and 1.9 x 10-6 m, (b) 0.97 eV and 1.3 x 10-6 m |
| | C) | (a) 0.85 eV and 1.9 x 10-6 m, (b) 0.54 eV and 8.2 x 10-7 m |
| | D) | (a) 1.13 eV and 1.9 x 10-6 m, (b) 0.1.8 eV and 2.3 x 10-6 m |
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| 7 | |
What is the wavelength of the series limit line for the hydrogen Paschen series? |
| | A) | 821 µm |
| | B) | 1.26 Mm |
| | C) | 273 nm |
| | D) | 821 nm |
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| 8 | |
The energy of photoelectrons emitted from a metal surface can be increased by |
| | A) | using light of higher frequency. |
| | B) | using light of longer wavelength. |
| | C) | using light of higher intensity. |
| | D) | using monochromatic, polarized light. |
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| 9 | |
The second series in the hydrogen spectrum is called the |
| | A) | Paschen series. |
| | B) | Lyman series. |
| | C) | Rydberg series. |
| | D) | Balmer series. |
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| 10 | |
The Bohr theory postulated the existence of |
| | A) | electromagnetic waves. |
| | B) | energy states in atoms. |
| | C) | electron waves. |
| | D) | photons. |
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