27 terms

Atomic Physics Review

energy of a photon depends on
planks constant
the ratio of energy to frequency for a given photon produces
small packet of electromagnetic energy that has particle-like properties
the kinetic energy of a photoelectron depends on
wavelength of light
in order for a photon to eject an electron from a metal's surface in the photoelectric effect
the frequency must be greater than a certain minimum value
when higher, more photons hit the material, and more are ejected. current and intensity are proportional. there is no change in energy per photon
when a light ray scatters from a material
the fractured beams will have a lower frequency
as a particle travels faster, its de Broglie wavelength
decreases (wavelength=h/p)
the reason the wavelike nature of a moving baseball is not noticed in everyday life is that
its wavelength is too small
Compton effect
shot x-rays at material, then they split and results had lower f
Compton shift
changes of wavelength after a photon collides with an electron
photon behavior
1) can be scattered after electron contact and lose energy
2) can knock electrons out of an atom
3)can knock to higher energy, is in an excited state
4) can create matter, electrons and positrons
pair production
photon disappears and an electron/positron pair is created. the reverse happens if an electron and positron collide
stopping potential
energy of electrons also known as the potential nedded to stop the current qV=KE
atomic mass
add the weights of protons and neutrons. subtract neutrons and everything else is protons
have same number of protons but different number of neutrons
protons and neutrons
fundamental forces
strong (holds nucleus), weak (electrons), attractive (positive negative), gravitational
alpha decay
strong nuclear force causes by the nucleus becoming too large (above 80). protons leave nucleus as helium atom is emitted as well as daughter element
beta decay
loses electrons from inner and a neutrino. an neutron splits and becomes a proton(B-). a beta particle is an electron
have zero charge and no mass, they decay by emitting a positron
gamma decay
nucleus is in excited state but drops to lower level. does not change atomic mass or number or neutrons
when nucleons join to form a stable nucleus
energy is released
the binding energy of a nucleus is contributed to
mass defect
binding energy per nucleon
is dependent on the particle
when a B+ particle is emitted from an unstable nucleus, the atomic mass number of the nucleus
decreases by one
the theory of special relativity
does not agree with traditional Newtonian mechanics