What is the energy of a mole of UV photons having a wavelength of 39 nm?

by Alfon…*

Question by s: What is the energy of a mole of UV photons having a wavelength of 39 nm?
A photon of ultraviolet (UV) light possesses enough energy to mutate a strand of human DNA. What is the energy of a single UV photon having a wavelength of 39 nm?
5.1e-18 J

that was the first question…but then it asks:
What is the energy of a mole of UV photons having a wavelength of 39 nm?
-the answer is in Joules

please explain it!

Best answer:

Answer by Paul B
If you know the energy of one photon, multiplying by Avogadro’s Number will give you the energy of a mole of photons of the same kind.

You may not be used to the idea of a mole of photons, but you can have a mole of anything. By the way, a mole of photons is called an Einstein.

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