What is the energy of a 0.07078nm photon?

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The energy of a 0.07078nm photon is calculated using the formula E = hc / lambda, resulting in an initial value of 17563.2 eV. However, the correct answer is 17520 eV, prompting a discussion on significant figures. The discrepancy arises from using more significant figures in the answer than in the input values. Adjusting the significant figures leads to a new calculation of 17514.8 eV, which is still below the expected value. Proper attention to significant figures is crucial for accurate results in such calculations.
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Homework Statement



Calculate energy of a 0.07078nm photon

Homework Equations



E = hc / lamda

The Attempt at a Solution



(6.63x10E-34)(3.0x10E8) / (7.078x10E-11)(1.60x10E-19)

=17563.2 eV

But the correct answer is 17520
 
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Close enough.
 
is it my sig figs?
 
Yes. You have way more sig figs in your answer than in your input values.
 
okay. Do I need to use 4 sig figs for all the values? I'm getting 17514.8 now. It's too low.
 

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