Quantum Mechanics

Which model of the atom said that electrons circle the nucleus in orbits of a fixed radius?

• Bohr model
• Quantum mechanical model
• Not true of either model
• Both Bohr and Quantum mechanical model

Which model of the atom said that electrons are allowed to have only certain energies?

• Bohr model
• Quantum mechanical model
• Not true of either model
• Both Bohr and Quantum mechanical model

Which was a limitation of the Bohr model of the atom?

• It was valid only for single electron atoms like Hydrogen
• It stated that only certain energies were allowed for electrons.
• It described the electron as a wave and a particle.
• None of these

The photoelectric effect only occurs if the light shining on the metal is:

• coherent.
• above a minimum intensity.
• above a minimum frequency.
• above a minimum wavelength.

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NGSS.HS-PS4-1

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Light of a single wavelength is incident on a metal.  Electrons are released. The intensity of the light is then increased.
Which of the following changes occur?

• Rate of electron emission: increase.
  Energy of electrons: increase.
• Rate of electron emission: decrease.
  Energy of electrons: no change.
• Rate of electron emission: decrease.
  Energy of electrons: increase.
• Rate of electron emission: increase.
  Energy of electrons: no change.

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NGSS.HS-PS4-3

Photons of energy 2.1 eV cause a photoelectric currenton the surface of caesium, which has a workfunction of 1.9 eV. How many times should the energyof the photon be increased in order to double themaximum kinetic energy of the photoelectrons?

• 2.18
• 1.09
• 3.28
• 4.36

Tags

NGSS.HS-PS4-3

Find the cut-off wavelength for the photoelectriceffect in tungsten (work function for tungsten is 4.5 eV)

• 138 nm
• 414 nm
• 552 nm
• 276 nm

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NGSS.HS-PS4-1

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Green light with a wavelength of 5461 Å, emitted from a mercury lamp, ejects photoelectrons with a maximum kinetic energy of 0.13 eV from a metal surface. Calculate the work function of the metal.

• 2.14 eV
• 1.07 eV
• 3.21 eV
• 0.535 eV

Tags

NGSS.HS-PS4-3

created an equation to treat the electron as a wave

• Planck
• Heisenberg
• de Broglie
• Schrodinger

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NGSS.HS-PS4-3

An excited state of an atom has an energy level of 2.5 eV.  The ground state of this atom is at 1.1 eV.  Which is the maximum energy of a photon emitted then an electron moves from the excited state to the ground state?

• 1.1 eV
• 1.4 eV
• 2.5 eV
• 3.6 eV

Tags

NGSS.HS-PS4-3