Unit 3 PreExam

The wave-particle duality of light describes light as...

• a wave only
• a particle only
• both a wave and a particle
• neither a wave nor a particle

A particle of light is called a photon.

• True
• False

A wave with a large wavelength will have a ______ frequency and _____ energy

• high, low
• high, high
• low, high
• low, low

Wave -particle duality is supported by...

• electrons behaving as particles with ordinary matter

• electrons behaving as waves when travelling through space

• the photo electric effect

• all of the above

This guy helped to explain the photoelectric effect with the equation E=hf and got the Nobel prize for it.

• Plank

• Einstein

• Heisenberg

• Young

The equation that shows the relationship between the energy of light and frequency is: 

• c= λ⋅f
• E=h⋅f

Calculate the energy of a gamma ray photon whose frequency is 5.02 x 10²⁰ Hz?

• 4.73 x 10⁷² eV

• 2.07 x 10 6 eV

• 3.33 x 10^-13 eV

• 1.21 x 10 ³⁵ eV

The relationship between wavelength and frequency is λ=c/f.  Calculate the wavelength of light that has a frequency of 5.2 x 10¹² 1/s. The speed of of light is 3.0x 10⁸ m/s.

• 5.8 x 10 ^-5 m
• 5.8 x 10 ^-7 m
• 5.19 x 10 ¹⁴ m
• 1.56 x 10 ²³ m

Which wave has a greater frequency?

• A
• B

The energy of photoelectrons emitted from a metal surface can be increased by

• using light of higher frequency.

• using light of longer wavelength.

• using light of higher intensity.

• using monochromatic, polarized light.