EM Radition and Quantum Phenomena Flashcards
Energy carried by a photon
E = hf = hc/λ
Threshold frequency
f = φ/h
How to find the maximum kinetic energy
hf = φ + Ek(max)
De Broglie wavelength
λ = h/mv
What is the work function of a metal
Energy required to break bonds holding electron to the metal’s surface
What is the stopping potential
The pd needed to stop the fastest moving electron
How does intensity of radiation relate to no of electrons emitted
Directly proportional
What shows light as a wave
Interference and diffraction
What shows light as a particle
Photoelectric effect
What did de Broglie suggest
If wave-like light showed particle properties, electrons should show wave-like properties
How to prove wave nature of electrons
Diffraction patterns are observed when accelerated electrons in a vacuum tube interact with spaces in a graphite crystal
Does larger wavelength reduce or increase spread of lines in a diffraction pattern
Increase spread of lines
What does it mean if an atom is ionised
Has lost an electron
What is the ionisation energy of an atom
The energy needed to remove an electron from an atom from the ground state (n=1)
Define the elecronvolt
The KE carried by an electron after it has been accelerated through a potential difference of 1 volt
