|
Title: What wavelength in nm of light sufficient energy per photon to dislodge an electron from the surface of soidiu? Post by: jtshnnon on Apr 7, 2013 The energy required to dislodge electrons from sodium metal via the photoelectric effect is 275 kj/mol. What wavelength in nm of light sufficient energy per photon to dislodge an electron from the surface of soidium?
How do you solve this? The book showed a diff example but not how to solve this one. Title: What wavelength in nm of light sufficient energy per photon to dislodge an electron from the surface of soidiu? Post by: ijr831 on Apr 7, 2013 Planck?s equation will help:
E = hf = hc / ? ? = hc / E where: h = 6.626 E-34 J/s f = frequency; c = speed of light = 3 E8 m/s; ? = wavelength Now: E = 275 kj/mol = 275,000 / 6.023 E23 J/atom (Note: 6.023 E23 = # atoms in a mole = Avagadro number) E = 2.75 E5 / 6.023 E23 E = 0.457 E-18 E = 4.57 E-19 J Now: ? = hc / E = 6.626 E-34 x 3 E8 / 4.57 E-19 ? = 4.35 E-7 ? = 435 E-9 m Answer = 435 nm |