How much energy would be required to excite one mole of hydrogen atoms from their ground state to n2?

The first thing that you need to do here is to figure out the wavelength of the photon emitted by the electron as it's making the n=3→n=2 transition. ... To find the energy difference for 1.00 moles of hydrogen atoms, you need to find the ... which tells you that 1 mole of photons will contain 6.022⋅1023 photons.

Explanation:

the awnser is group 12