calculate the wavelength of the second line in the Brackett series (nf=4) of the hydrogen emission spectrum. Rh= 2.180e-18

Question

any help please? i know its energy levels 4 to 6... but that is all.

Answer 1

1/lambda= R (1/4^2-1/662) R= Rydberg constant = (1.09678E7 m^-1)

A little algebra changes this to

1/lambda= R (36-16)/(16*36)

solve for lambda.

Answer 2

Not a presice
answer