1. Bohr's first postulate
    An electron in an atom exists in only certain stable, circular orbits called "Energy levels"
  2. Bohr's second postulate
    • An electron absorbs energy to jump from a lower orbit to a higher orbit
    • An electron emits energy when it falls from a higher orbit to a lower orbit
  3. Bohr's third postulate
    • The only orbits (energy levels) an electron can exist are those with the angular momentum = nh/2π
    • m0vrn = nh/2π
  4. ν = c/λ

    Frequency (ν) = Hz
    Wavelength (λ) = m
    Velocity (c) = m/s
    c = 3 x 108m/s
  5. E = E2 – E1

    = hν
    = h c / λ

    h = Planck’s constant
    = 6.626 x 10-34 Joule.sec
  6. F = e2/4πεoεr2 N

    e = electron charge, r = distance of separation (m),
    εo = permittivity of free space = 8.854 x 10-12 F /m,
    ε = dielectric constant of the medium.
  7. En = -13.6 / n2 eV

    rn= 0.53 n2 A
  8. Ionization energy is....
    • is the energy required by an electron to leave the atom.
    • i.e. the electron in an atom should get sufficient energy to reach
  9. The maximum number of electrons that can occupy an energy level in any atom
    = 2n2

    [where n is the order of the energy level (n=1,2,3,4,….).]
  10. Bohr’s atom model explains the behaviour of hydrogen atom.
Card Set
Chapter 1