Flashcards in Atomic Phenomena Deck (15):
Thermal Blackbody Radiation
All matter will emit electromagnetic radiation as long as the temperature is above absolute zero
How do scientists approximate blackbody radiation?
Cavity radiation, which is the radiation produced in a cavity within a hot object
h = 6.63 X 10^-34 J s = 4.14 X 10^-15 eV s
What does the blackbody curve show?
The blackbody spectrum is energy radiated plotted against light wavelength and it shows the amount of energy radiated as a function of wavelength. There is one wavelength were the maximum amount of energy radiates, dependent upon absolute temperature of the blackbody.
Wien's Displacement Law
λ(peak) T = constant = 2.90 X 10^-3 m K
E(T) = σT^4
σ = 5.67 X 10^-8 J/ (s m^2 K^4)
Electron expulsion after metal sheet hit with light of certain frequency discovered by Heinrich Hertz in 1887
The minimum frequency of light that ejects an electron dependent on the type of metal exposed
Energy of the photon of light
E = hf = hc/ λ
What type of light has higher energy?
Higher frequency/ shorter wavelength
Maximum Kinetic Energy of Ejected Electron
KE = hf - W = hf - hf(threshold)
Bohr Model of Hydrogen Atom
There are specific stable orbits of quantized energy where electrons do not radiate energy, where the energy is negative until reaching 0 eV and becoming unbound. The ground state of Hydrogen is -13.5 eV and E(n) = -13.6/ n^2 in Hydrogen
Emission and Absorption of Light
1. Stable and discrete energy level
2. Electrons emit or absorb radiation ONLY during transition from one energy level to another
3. Electron absorbs a right frequency proton when moving to higher energy
4. Electron emits photon when moving to lower energy
While emitting or absorbing photons, the frequency will allow for hf to be the difference between the two energy levels
When moving to higher energy, electron will emit color while absorbing photon.