Flashcards in Chapter 9- Atomic And Nuclear Phenomena Deck (13)
When light of a sufficiently high frequency (blue to UV) hits metal the metal will emit electrons. These electrons produce a current
Energy of emitted photon from photoelectric effect
E = hf
h- plancks constant (6.626 x 10^-34)
Maximum kinetic energy of ejected electron
Kmax = hf-W
W- work function is the minimum energy required to eject an electron W=hf(threshold)
Particle theory of light
Light is not a continuous wave, but acts as a discrete bundles of energy called photons
What does threshold frequency depend on?
Type of metal
Equation that explains mass defect
E = mc^2
Large nuclei splitting into smaller nuclei. Rarely spontaneous.
Emission of alpha particle. 4-2He (2 protons and 2 neutrons leave) - they have a +2 charge
Emission of beta particle. Electron given off only but a neutron is converted into a proton as well.
Emission of gamma ray (high energy photon). No change in number of protons, neutrons, or electrons.
Reverse beta decay. Takes away one proton.
n = n*e^(-wvlt)
Wvl- .693/half life