Finding B-field from Zeeman effect pattern

[maximus123]

Hey

I have this problem

Homework Statement

A source which emits a line at 500nm is found to exhibit the normal Zeeman effect
when placed in a magnetic field. Calculate the magnetic field given that the separation
of adjacent components in the Zeeman pattern is 12.0pm.

Homework Equations

I have this equation from my textbook

ΔE = μ_bBgm_j

The Attempt at a Solution

I am assuming that I need to use the fact given about the distance of the components in the pattern to find ΔE and then rearrange for B, but I am not sure how to do that.

Any help would be appreciated

Thanks

 

[TSny]

Recall that E = hf and f = c/λ. See if you can write ΔE in terms of Δλ and λ of the source.