The electron energy in hydrogen atom is given by En = (–2.18 × 10–18)/n2 J. Calculate the energy required to remove an electron completely from the n = 2 orbit. What is the longest wavelength of light in cm that can be used to cause this transition?
The expression for the energy of hydrogen of electron is
En = -2π2me4Z2/n2h2
Where m= mass of electrons
Z=atomic mass of atom
e = charge of electron
h = planck’s constant
When n = 1 then En = - (2.18X10-18 ) (GIVEN)
When n = 2 then En= - (2.18X10-18 )/4 = 0.5465X10-18 J
Therefore the energy required for ionization from n = 2 is 5.45 x 10-19 J
Now wavelength of light needed
= E=hv = hc/λ
Or
λ = [{(6.62x10-24)(3x108)} / 5.45] x 10-19 = 3647
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5 Comment(s) on this Question
5.45*10to the -19
All wrong value of plank constant is 6626.10power_34
the answer is also wrong with no specified unit
The value of planck's constant is wrong.
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