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EM radiation and quantum phenomena - Coggle Diagram
EM radiation and quantum phenomena
photoelectric effect
work function is the minimum amount of energy required to release electrons from the surface of a metal
E=hf0
electrons are emitted if the incident radiation is above a given
threshhold frequency
Photoelectric equation
hf = work function + Ek
stopping potential
- the minimum opposing voltage required to stop the most energetic photoelectrons from reaching the collector plate
collisions of electrons with atoms
excitation
is when a an electron transfers energy to the atom
potential for electrons in the atoms shells to gain enough energy to break free causing the atom to ionise
1 electron volt = 1.6 x 10^-19J
Fluorescent tubes
a high voltage produces free electrons in the tube
which excites the mercury atoms that release UV light when they de-excite
a phosphor coating on the inside of the tube absorbs the UV light exciting its electrons
which then emits visible light as the electrons de-excite
line spectra - distinct patterns of light emitted or absorded by elements
wave-particle duality
electron diffraction suggests that particles possess wave properties
photoelectric effect suggests that electromagnetic waves have a particulate nature
de Boglie wavelength - the wavelength associated with any moving particle or object
h / (mv)