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Atom Systems

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  • The electron cloud model keeps quantized energy levels.
    True
    False
  • Compared to Bohr, the electron cloud model is better for:
    Predicting chemical behavior
    Explaining hydrogen spectra only<br>
    Describing photons
    Ignoring energy levels
  • Scientists only need one model to explain all atomic behavior.
    True
    False
  • The electron cloud model shows electrons as:
    Probability regions
    Fixed orbits
    Stationary particles
    Circling nuclei like planets
  • Observable phenomena of atoms include:
    Both a and b
    Photoelectric effect
    Neither
    Spectral lines
  • Which model best predicts chemical behavior and probabilistic electron locations?
    Dalton
    Classical
    Electron cloud
    Bohr
  • Classical physics predicted that electrons orbit the nucleus like:
    Planets around the sun
    Fixed points
    Satellites randomly
    Particles in a cloud
  • Electron transitions in Bohr’s model produce:
    No energy
    Only infrared light
    Discrete spectral lines
    Continuous radiation
  • Increasing light intensity can eject electrons if the frequency is too low.
    True
    False
  • Which formula represents photon energy?
    V = IR
    E = hf
    E = mc²
    F = ma
  • Photon emission occurs when an electron absorbs energy and jumps to a higher level.
    False
    True
  • Bohr’s model works perfectly for multi-electron atoms.
    False
    True
  • Einstein explained the photoelectric effect using:
    Bohr’s orbitals
    Photon theory (light as particles)
    Continuous wave theory
    Classical electricity
  • According to classical physics, atoms should:
    Collapse due to spiraling electrons
    Be stable
  • Which of the following is a limitation of Bohr’s model?
    Does not have energy levels
    Cannot predict hydrogen spectrum
    Cannot explain multi-electron atoms
    Ignores the nucleus
  • What happens when an electron jumps from a higher to a lower energy level?
    Nothing happens
    A photon is absorbed
    Electron disappears
    A photon is emitted
  • Which parts of the atom interact to produce spectral lines?
    Nucleus and electrons
    &nbsp;Only the nucleus
    Neutrons and photons
    Only photons
  • In Bohr’s model, electrons:
    Move in fixed circular orbits
    Are stationary
    Exist only in a cloud
    Can have any energy
  • Classical physics could explain discrete spectral lines.
    False
    True
  • In the photoelectric effect, electrons are ejected when:
    Light frequency is above threshold
    Light intensity is high enough
    Metal is hot
    Any light shines on the metal