Question

What is the energy of a single photon of microwave radiation with a wavelength of 0.0522 meters?

Which of the following electron transitions in the hydrogen atom is associated with radiation having the longest wavelength?

You can do four different calculations, but that might take you awhile. You should be able to do this problem without performing a single calculation.

Select one:

a. from n = 5 to n = 3

b. from n = 4 to n = 1

c. from n = 3 to n = 1

d. from n = 6 to n = 3

Answer 1

1)

Given:

lambda = 5.22*10^-2 m

use:

E = h*c/lambda

=(6.626*10^-34 J.s)*(3.0*10^8 m/s)/(5.22*10^-2 m)

= 3.808*10^-24 J

Answer: 3.81*10^-24 J

2)

As the value of n increases, the difference between the subsequent energy levels decreases.

So, the energy difference is lowest for n=5 to n=3.

Since energy and wavelength are inversely related, wavelength will be highest in this case

Answer: a