Background Info Flashcards
Idea of energy being quantised
If we consider a proton with energy E=hv
v is frequency, if we consider wave particle duality the only way to increase this value is via more photons, so E = n*hv where n is an integer - so quantised
Electron volt:
E =QV, V = 1V, Q = 1.6*10^-19C
Wavenumber
1/λ, v=c/λ=cvbar
Photoelectric effect
When light of a sufficient frequency strike a metal plate a photoelectron is expelled.
How photoelectric effect shows quantisation
In dim light only a few high energy photo electrons are released, can only occur if light is a bundle of photons, where a photon has transferred all of its energy to the electron, so energy of light depends on number of photons, n = 1,2,3…
Atomic line spectra
Spectral line produced when excited electron drops to original energy level releasing a photon of equivalent energy ergo frequency to the gap
Work function
Like ionisation energy, different for each material and energy level but is the minimum energy required for a photoelectron to be produced
Work function and energy equation
hv = phi + 1/2mv^2
Compton scattering experiment
When photon strikes an electron it increases its momentum and scattered photon is of higher wavelength so lower energy.
How do electrons act in the bohr model
Like a standing wave, which is constructively interfering
Standing wave equation for L and for r
λ = 2L/n and λ = 4pir/n
De Broigle wavelength equation
λ = h/p
