Modern

The graph shows maximum kinetic energy of emitted electrons against frequency of incident light for a number of different metals.

The threshold frequency is determined by:

• the x-intercept.

• the y-intercept.

• the slope.

• the area under the graph.

The graph shows maximum kinetic energy of emitted electrons against frequency of incident light for a number of different metals.

The work function is determined by:

• the x-intercept.

• the y-intercept.

• the slope.

• the area under the graph.

High energy light consist of ________ wavelength and _______ frequency

• Short, Low

• Long, Low

• Short, High

• Long, High

In a radioactive decay, neither the atomic number nor the mass number changes.

Which of the following particles is emitted in the decay?

• proton

• neutron

• electron

• photon

Which particles are not affected by the strong force?

• hadrons
• protons
• neutrons
• electrons

When an atom undergoes radioactive decay,  the energy that is released is due to: 

• Gravity 
• Electromagnetism 
• Strong Nuclear 
• Weak Nuclear 

Tags

NGSS.HS-PS1-8

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 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

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.

Photons of energy 2.1 eV cause a photoelectric current on the surface of cesium, which has a work function of 1.9 eV. How many times should the energy of the photon be increased in order to double the maximum kinetic energy of the photoelectrons?

• 2.18

• 1.09

• 3.28

• 4.36