atomic physics Flashcards
gamma decay
gamma particle (Ɣ - high energy photon) is emitted after alpha or beta decay
alpha decay
helium+2 (2 protons, 2 neutrons) is emitted
beta+ decay
positron and neutrino are emitted
beta- decay
electron and antineutrino are emitted
DeBroglie Relationship
λ = h/mv
Linear momentum of electron (Bohr)
p = (n*h)/(2*π*r) = n*ħ/r
Angular momentum of electron
p=n*h/2*π = n*ħ
*note: not dependent on radius
Energy of electron (Bohr)
E = -(mZ2e4)/(8n2h2ε02)
orbital radius of electron (Bohr)
r = (n2h2ε0)/(Z*π*m*e2)=n2a0/Z
Bohr radius
radius of 1st electron (hydrogen atom)
a0=h2*ε0/π*m*e2<br></br> = 0.0529nm
shortcomings of bohr model
1) doesnt explain spectral lines
2) violates uncertainty principle
Valence shell capacities
- 2
- 8
- 18
- 32
subshell names and capacities
in shell 1:
1s
in shell 2:
2s 2p
in shell 3:
3s 3p 3d
in shell 4:
4s 4p 4d 4f
s shells hold 2 electrons
p shells hold 6 electrons
d shells hold 10 electrons
f shells hold 14 electrons
g shells hold 18 electrons
Stephan Boltzman law
j* = σT4
P = AεσT4
ε = emissivity of object (for perfect blackbody, 1)
j* = emissive power
Wien’s displacement law
λmaxT = b
b = Wien’s constant
Weak force interaction
responsible for beta decay
Fermions
quantum numbers described by pauli-exclusion principle
1/2 integer spin
types of fermions: quarks, leptons, any particle with odd combination of these, baryons
antisymmetric wave functions
Quarks
itneract through strong interaction
only known carriers of fractional charge
Leptons
Do not interact through strong interaction
electrons, muons, taus
Bosons
have integer spins
photons, gluons, graviton
symetric wave functions
Strong force interaction
pion interaction between particles
photoelectric effect
eV = hf + φ
φ -> work function of metal
e -> charge of electron
V -> stopping potential
f -> frequency of emmited light
change in wavelength for compton scattering
λ’ - λ = h/(mec)
Bremsstrahlung radiation
breaking radiation from accelerated electrons into metal target
causes x-ray radiation
kenetic energy for electron for x-ray radiation
E = hc/λc
λc -> cutoff radiation
antiparticle of photon
photon!
difference between neutrino and antineutrino
neutrino lepton number is +1
antineutrino lepton number is -1
pion decay
π- -> μ- + ν
π+ -> μ+ + ν
particle that confirmed the eightfold way
Ω-
arangement of particles based on lepton number and strangeness
pauli’s exclusion principle
no 2 electrons cannot occupy the same state. applies to particles with 1/2 integer spin
J/ψ particle
electrically neutral
very heavy
led to discovery of charmed quarks (particle is bound state of charmed quarks)
muon decay
μ+ -> e+ + ve + vμ
muon decays into positron and 2 neutrinos (electron neutrino and muon antineutrino)