## hw 1.23 [ENDORSED]

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Emely Reyna 1F
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Joined: Fri Apr 06, 2018 11:04 am

### hw 1.23

Problem 1.23 asks to calculate the wavelength of a photon emitted with energy of 140.511 keV. How would I convert keV into J?

Chem_Mod
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### Re: hw 1.23  [ENDORSED]

1eV is equal to 1.6x10^-19J and there are 1000 eV in 1 keV.

Rebecca Chu 1C
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Joined: Fri Apr 06, 2018 11:02 am

### Re: hw 1.23

1 keV = 1.602 x 10^-16 J so you use dimensional analysis to convert keV to Joules.
140.511 keV x [(1.602 x 10^-16) J / 1 keV] = 2.251 x 10^-14

Andrew Evans - 1G
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### Re: hw 1.23

Yeah, but please don't bother memorizing that number, they give it on the front page of the test with all the other constants and equations.
;)
-Andrew Evans
Section 1G

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