- #1

Master J

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## Homework Statement

"Mono-energetic electrons are diffracted by a lattice. Their wavelength is shown to be L=0.35nm. What are the energies of the electrons?"

## Homework Equations

E=hf

c=hL

## The Attempt at a Solution

c/L gives 8.566exp17

h=6.626exp-34

I plug them in and get: 5.66exp-19 J

The answer is 1184.4 kJ mol -1.

So I divide my answer by 1000, and multiply it by Avogadros number. But my answer is nowhere near the actual answer. Where am I going wrong?