What is (delta E) for the traansition of an electron from n=9 to n=4 in a Bohr hydrogen atom?

Question

What is the frequency?

Thank you!

Answer 1

dE = 2.18E-18 J*(1/16 - 1/81)

c = freq x wavelength = 3E8 m/s

Answer 2

Thank you!! You are so helpful!