Question

An electron transitions from n = 5 to n = 3 in a hydrogen atom. What is the energy required for this transition? Is energy emitted or absorbed in the transition?

Answer 1

En​=− 13.6/(n^2)​ eV. is the energy in each level.
so figure for n=5, then n=3
subtract the n=5 energy from the n=3 level.

Answer 2

So is it emitted or absorbed?

Answer 3

Think about it. The proton is + charged. The electron is - charged. Does it take energy or give up energy to SEPARATE A + AND A - CHARGE. For an electron to move from farther away to closer . energy change will be the opposite.