line spectra - spectrum containing radiation of specific wavelengths  

• monochromatic radiation - consists of a single wavelength
• spectrum - separation of radiation into different wavelengths
• continuous spectrum - contains light of all wavelengths

Rydberg equation - allowed calculation of wavelengths of all spectral lines  

• 1/l = (Rh)(1/n12 - 1/n22) = [(2.18 x 10-18 J) / hc] (1/n12 - 1/n22)
• Rh = 1.096776 x 107 m-1

Bohr's Model - electrons moving in circular paths lose energy and spiral towards nucleus  

• only orbits w/ certain radii, dependent on energies of electrons
• electron in allowed energy state has specific energy, doesn't radiate energy
• energy emitted/absorbed by electrons when it changes energy states
• E = (-2.18 x 10-18 J)(1/n2) = energy in hydrogen atom
  • n = integer from 1 to ¥ = quantum number
  • ground state - lowest energy state
  • excited state - higher energy state
  • E = (-2.18 x 10-18 J)(1/¥2) = 0
• DE = Efinal - Einitial = Ephoton = hn = hc/l = (-2.18 x 10-18 J)(1/nf2 - 1/ni2)
  • ni = initial energy state
  • nf = final energy state
  • l = hc / DE
  • n = = DE / h
• doesn't explain spectra of any atom besides hydrogen
• electrons actually show properties of waves

Find the de Broglie wavelength of an electron w/ velocity 5.97 x 106 m/s  

• Given:
  • l = h/(mv)
  • m = 9.11 x 10-28 g = 9.11 x 10-31 kg
  • h = 6.63 x 10-34
  • v = 5.97 x 106
• l = (6.63 x 10-34) / (9.11 x 10-31 x 5.97 x 106)
• l = 1.22 x 10-10 m