I need to calculate the maximum energy of a liberated photoelectron.

h = 6.63x10^-34J
w = 2.1eV
e = 1.6x10-19C
(wave length) = 430nm (4.30x10^-7m)
C = 3x10^8

I have the equation E = hf - w

and f = c/(wavelength)

So the kinetic energy E is;-

E = (hc)/wavelength - w.

I've done this but the answer in the book isn't the same I was wondering if I am aproaching this incorrectly or if I have made a mistake.

NOTE i HAVE CONCERTED THE eV into joules 2.1eV x 1.6x10^-19C = 3.36x10^-19J

My final equation is

(6.63x10-34 x 3x10^8)/4.3x10^-7 - (3.36x10^-19) = 4.63x10^12J.

Question

I need to calculate the maximum energy of a liberated photoelectron.

h = 6.63x10^-34J
w = 2.1eV
e = 1.6x10-19C
(wave length) = 430nm (4.30x10^-7m)
C = 3x10^8

I have the equation E = hf - w

and f = c/(wavelength)

So the kinetic energy E is;-

E = (hc)/wavelength - w.

I've done this but the answer in the book isn't the same I was wondering if I am aproaching this incorrectly or if I have made a mistake.

NOTE i HAVE CONCERTED THE eV into joules 2.1eV x 1.6x10^-19C = 3.36x10^-19J

My final equation is

(6.63x10-34 x 3x10^8)/4.3x10^-7 - (3.36x10^-19) = 4.63x10^12J.

anonymous · Answer

The answer in the book is 1.27x10^-19J, I also tried calculating in eV in case they made a mistake.

tcy · Answer

book answer is correct, be careful of your calculation

anonymous · Answer

did you play your values on a calculator??? I want to be sure

anonymous · Answer

i just played your final equation on a calculator, and i got the book's answer,,,,

anonymous · Answer

Yea turns out I just made a bloody typo -.-......