Powerpoint 4 Flashcards
What is the relationship between speed, wavelength, and frequency?
c=λν, where
c is the speed of light,
λ is wavelength, and
ν is frequency.
What is the speed of light?
3.00×10^8 m/s.
What is the visible light spectrum range in nanometers?
400nm (violet) to 750nm (red).
What happens to wavelength and frequency when one increases?
They are inversely proportional.
What is Planck’s constant?
h=6.626×10^−34 Js.
What is the equation for energy of a photon?
E=hν, where
E is energy,
h is Planck’s constant, and
ν is frequency.
What is the photoelectric effect?
The emission of electrons when light of a certain frequency shines on a metal.
What is the work function in the photoelectric effect?
The minimum energy or frequency required to eject an electron from a metal.
Who was Max Planck, and what did he contribute?
Max Planck (1858-1947) proposed that energy is quantized and can only be emitted or absorbed in discrete multiples of hv (quanta).
What is the ultraviolet catastrophe, and how did Planck solve it?
Classical physics predicted infinite energy at short wavelengths, which was incorrect. Planck’s quantum theory solved this by proposing quantized energy levels.
What did Albert Einstein propose about light?
Einstein suggested that light consists of particles (photons) that have energy equal to E=hν. This explained the photoelectric effect.
What was the historical importance of Planck’s constant?
It marked the beginning of quantum mechanics, fundamentally changing our understanding of atomic and subatomic behavior.
What is the relationship between energy (E) and frequency (ν)?
Directly proportional.
What is the relationship between energy (E) and wavelength (λ)?
Inversley proportional.
What is the relationship between frequency (ν) and wavelength (λ)?
Inversely proportional.
