atomic structure formulas and small notes Flashcards
energy of electron
hf=hc/lambda
the energy of nth Bohr orbit
-2.18*10^-18(z²/n²) J
= 13.6(Z²/N²) eV
The radius of an nth orbit
0.529 n²/z angstrom
the velocity of nth orbit
2.18*10⁶ z/n
de-Broglie wavelength
lambda=h/mv or h/mc = h/p
the wavelength of an emitted photon
r z²( 1/n₁² - 1/n₂²)
for hydrogen,
1.09677*10⁷( 1/n₁² - 1/n₂²)
Number of photons emitted by a sample of H atom
n(∆n-1)/2
Heisenberg’s uncertainty principle
∆x.∆p > h/4∏
or m∆x∆v ≥ h/4∏
no. of emission lines
n(n+1)/2
absolute charge of e-
-1.602* 10^-19 C
mass of e-
9.11* 10^-31 kg
planck’s constant
6.626*10^-34 Js
em spectrum arranged in ascending order of wavelength
cosmic rays gamma rays X-rays UV rays visible rays IR rays microwaves radiowaves
photoelectric effect
the phenomenon of ejection of electrons when certain metals(K, Rb, Cs, etc) are exposed to a beam of light having a certain minimum frequency known as threshold frequency
expression of photoelectric effect
hf= hf₀+½mv²
