Can any one help me with this question? Thanx(adsbygoogle = window.adsbygoogle || []).push({});

Calculate the frequency of the photon emitted when an electron in an atom changes from (-2.42e-19 joules) to (-21.76e-19 joules).

I know that i'm going to use E=hf and h=6.63e-34. I'm not sure what I do with the 2 enery levels, do i subtract them?

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# Quantinzation of Energy & Planck help!

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