U2.5-2.6 Photoelectric Emissions, Energy Levels And Wave Particle Duality Flashcards
1
Q
What is a photon
A
A packet of electromagnetic energy
2
Q
What are the equations for photon energy
A
E = h f
E = h c / lambda
h = planks constant
c = speed of light in a vacuum
f = frequency of the radiation
Lambda = wavelength of the radiation
3
Q
What is photoelectric emission
A
Electrons are ejected from the surface of a metal when electromagnetic radiation (usually visible or UV) of sufficiently high energy falls on it.
4
Q
What is the equation for photoelectric emission
A
Energy of incident photon = work function of metal surface + maximum KE of emitted photoelectrons
hf = hf0 + 1/2 m (vmax)2
5
Q
What is the definition of the work function of a surface
A
The minimum energy needed to liberate an electron from the surface
