calculate the energy of a photon emitted when an electron in a hydrogen atom undergoes a transition from

Question

n=5 to n=1
how do I do this?

Answer 1

E = 2.180E-18 J*(1/1^2 - 1/5^2)

Answer 2

I think I am doing something wrong.
I keep coming up with 8.72x10^17 and it is telling me I am wrong.

I know D E=2.18x10^-18 x (1/1^2-1/5^2)

Answer 3

i think I am not doing this part right
(1/n5^2 - 1/n1^2)

Answer 4

2.0928 x 10(to the power of -18)