Maximum possible kinetic energy of the emitted electrons

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MorganYun1H
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Maximum possible kinetic energy of the emitted electrons

Postby MorganYun1H » Mon Oct 09, 2017 9:43 am

If molybdenum is irradiated with 194 nm light, what is the maximum possible kinetic energy of the emitted electrons? The calculated minimum work is 7.22x10^-19J

Please show work

Chem_Mod
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Re: Maximum possible kinetic energy of the emitted electrons

Postby Chem_Mod » Mon Oct 09, 2017 2:20 pm

If molybdenum is irradiated with 194 nm light, what is the maximum possible kinetic energy of the emitted electrons? The calculated minimum work is 7.22x10^-19J

Hi Morgan,

Remember this equation:
hv - phi = KE

h = Planck's constant
v = frequency
phi = work function
KE = kinetic energy

Therefore, the maximum possible kinetic energy is hv - phi.
Substitute what we know:
hv - phi
hc/lambda - phi
(6.626 x 10^-34 J s) * (3 x 10 ^8 m/s) / (194 x 10^-9 m) - 7.22 x 10^-19 J
= ___ J

MorganYun1H
Posts: 59
Joined: Thu Jul 13, 2017 3:00 am

Re: Maximum possible kinetic energy of the emitted electrons

Postby MorganYun1H » Mon Oct 09, 2017 2:39 pm

Oh ok, I understand. Thank you!


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