Photon energy

EPhoton=hcλ=hf=ωE_{Photon} = \frac{hc}{\lambda} = hf = \hbar\omega

Photoelectric effect

hf=WOut+K=WOut+eU0hf = W_{Out} + K = W_{Out} + eU_0

DeBroglie wavelength

λ=hp=hmv\lambda = \frac{h}{p} = \frac{h}{mv}

Square well potential

En=(h28mL2)n2E_n = \left(\frac{h^2}{8mL^2}\right) \cdot n^2
Ψn(x)=2Lsin(nπxL)\Psi_n(x) = \sqrt{\frac{2}{L}} \sin \left( n\frac{\pi x}{L} \right)

Bohr radius

r=ϵ0h2πμe2n2Za0n2Zr = \frac{\epsilon_0h^2}{\pi \mu e^2}\frac{n^2}{Z}\approx a_0 \cdot \frac{n^2}{Z}
a0=0.529  A˚a_0=0.529 \; \textup{Å}

Rydberg's formula

1λ=RMZ2(1n121n22)\frac{1}{\lambda} = R_M \cdot Z^2 \left( \frac{1}{n^2_1} - \frac{1}{n^2_2} \right)
RM=e48ε02h3cμR_M = \frac{e^4}{8 \varepsilon^2_0 h^3 c}\cdot \mu
μ=mMm+M  Reduced mass\mu = \frac{m \cdot M}{m + M} \; \textup{Reduced mass}
RM=RMM+mR_M = R_\infty \cdot \frac{M}{M+m}
R=109737.31568  cm1R_{\infty} = 109737.31568 \; \textup{cm}^{-1}

Energy levels in Hydrogen

En=Z2E0n2    where    E0=mk2e422=13.6  eVE_n = -Z^2 \frac{E_0}{n^2} \;\; \textup{where} \;\; E_0 = \frac{mk^2 e^4}{2 \hbar^2} = 13.6 \; \textup{eV}

Quantized angular momentum z component

L=l(l+1)L = \hbar \sqrt{l(l+1)}

Quantized angular momentum

L=l(l+1)|L| = \hbar\sqrt{l(l+1)}

Ratio between the proton mass and the electron mass

mpme=1836.152673\frac{m_p}{m_e} = 1836.152 673

Characteristic X-ray emission

1λKα=34R(Z1)2\frac{1}{\lambda_{K_{\alpha}}} = \frac{3}{4}R_{\infty} \cdot (Z-1)^2
1λLα=536R(Z7.4)2\frac{1}{\lambda_{L_{\alpha}}} = \frac{5}{36}R_{\infty} \cdot (Z-7.4)^2

Bremsstrahlung

λmin=hceU\lambda_{min} = \frac{hc}{eU}

Reduced mass

μ=m1m2m1+m2\mu = \frac{m_1 m_2}{m_1 + m_2}

Moment of inertia

I=μr2I=\mu r^2

Angular momentum

L=μrv=μr2ω=IωL = \mu r v = \mu r^2 \omega = I\omega

Rotational energy diatomic molecule

Erot=l(l+1)22I,  I=μr2E_{rot} = \frac{l(l+1)\hbar^2}{2I}, \; I=\mu r^2

Rotational constant

B=E0r=22IB = E_{0 r} = \frac{\hbar^2 }{2 I}

Vibrational energy diatomic molecule

Evib=ω0(ν+1/2)E_{vib} = \hbar \omega_0 \cdot (\nu + 1/2)

Fermi energy at T=0 K

EF=h28m(3πn)2/3,where n is the electron densityE_F = \frac{h^2}{8m}\left( \frac{3}{\pi}n\right)^{2/3}, \textup{where n is the electron density}

Fermi temperature

TF=EFkT_F = \frac{E_F}{k}

Fermi speed

uF=2EFmeu_F = \sqrt{\frac{2 E_F}{m_e}}

Free electrons in conductors

ne=fρNAM,where f is the number of free electrons per atomn_e = f \cdot \frac{\rho \cdot N_A}{M}, \textup{where f is the number of free electrons per atom}

Resestivity

ρ=mevavnee2λ\rho = \frac{m_e v_{av}}{n_e e^2 \lambda}

Mean free path

λ=vtnionπr2vt=1nionπr2=1nionA\lambda = \frac{v t}{n_{ion} \pi r^2 v t} = \frac{1}{n_{ion} \pi r^2} = \frac{1}{n_{ion} A}

Specific heat due to conduction electrons

cv=12π2RTTFc_v = \frac{1}{2} \pi^2 \cdot R \cdot \frac{T}{T_F}