Ionization involves completely removing an electron from an atom. light of a particular wavelength can cause ionization to occur
if it has the required energy. the energy to ionize a certain element is 342 kj/mol. what wavelength contains enough energy in a single photon to ionize one atom of this element?
<span>350 nanometers
We first need to calculate how much energy is needed to ionize a single atom. So divide the kilojoules/mol energy value by avogadro's number.
342 kj/mol / 6.0221409x10^23 = 5.67904x10^-19 Joules
So we need a photon with 5.67904x10^-19 Joules of energy. The equation to express the energy of a photon is
E = hc/w
where
h = Planck constant (6.626070040Ă—10â’34 Js)
c = speed of light (299792458 m/s)
w = wavelength of photon
Solving for w
E = hc/w
Ew = hc
w = hc/E
Substituting known values
w = 6.626070040Ă—10^â’34 Js * 299792458 m/s / 5.67904x10^-19 J
w = 1.9864458x10^-25 Jm / 5.67904x10^-19 J
w = 3.497855x10^-7 m
w = 3.50x10^-7 m
w = 350 nm</span>