21.1 Planck and Quantum Nature of Light
A perfect blackbody is a perfect absorber of energy transferred by what method?
Which of the following is a physical entity that is quantized?
- electric charge of an ion
- frequency of a sound
- speed of a car
Find the energy in joules of photons of radio waves that leave an FM station that has a 90.0-MHz broadcast frequency.
- 1.8 × 10−25 J
- 1.11 × 10−25 J
- 7.1 × 10−43 J
- 5.96 × 10-26 J
Which region of the electromagnetic spectrum will provide photons of the least energy?
- infrared light
- radio waves
- ultraviolet light
Given two stars of equivalent size, which will have a greater temperature: a red dwarf or a yellow dwarf? Explain. Note—Our sun is considered a yellow dwarf.
- a yellow dwarf, because yellow light has lower frequency
- a red dwarf, because red light has lower frequency
- a red dwarf, because red light has higher frequency
- a yellow dwarf, because yellow light has higher frequency
21.2 Einstein and the Photoelectric Effect
What is a quantum of light called?
Which of the following terms translates to light-producing voltage?
- quantum mechanics
21.3 The Dual Nature of Light
What two particles interact in Compton scattering?
- photon and electron
- proton and electron
- neutron and electron
- proton and neutron
What is the momentum of a 500-nm photon?
- 8.35 × 10−26 kg ⋅ m/s
- 3.31 × 10−40 kg ⋅ m/s
- 7.55 × 1026 kg ⋅ m/s
- 1.33 × 10-27 kg ⋅ m/s
The conservation of what fundamental physics principle is behind the technology of solar sails?
- angular momentum
Terms like frequency, amplitude, and period are tied to what component of wave-particle duality?
- neither the particle nor the wave model of light
- both the particle and wave models of light
- the particle model of light
- the wave model of light
Why was it beneficial for Compton to scatter electrons using X-rays and not another region of light like microwaves?
- because X-rays are more penetrating than microwaves
- because X-rays have lower frequency than microwaves
- because microwaves have shorter wavelengths than X-rays
- because X-rays have shorter wavelength than microwaves