Calculate energy of transition from n=3 to n=1. What region of electromagnetic spectrum is this radiation found?

1 Answer
May 29, 2016

Since you did not specify, I'm going to assume you mean, hydrogen with a single electron.

#E_"ph"=1.89# #"eV"#

#lambda=655.2#, this is in the optical (it's a red-pink)

Explanation:

The formula

#E_"ph"=hcR((1/n_"lower")^2 - (1/n_"upper")^2)#

#hcR=13.6# #"eV"#

#E_"ph"=13.6# #"eV" ((1/2)^2 -(1/3)^2)#

#E_"ph"=13.6# #"eV" (1/4 - 1/9)#

#E_"ph"=13.6# #"eV" ({5}/36)=1.89# #"eV"#

#E_"ph"=h(c/lambda)=hcR {5}/36#

#1/lambda=R {5}/36#

#lambda=1/R 36/5#

#1/R# is a constant and #91# #"nm"#

#lambda=655.2#, this is in the optical (it's a red-pink)