High-pressure sodium vapor lamps are used in street lighting. The two brightest lines in the sodium spectrum are at 589.00 and 589.59 nm. What is the diffrence in energy per photon of the radiations corresponding to these two lines?

3 answers

E=planksconstant*(c/lambda)
= k*c (1/589nm -1/589.59nm)
= k*c*(589.59-589)/589*589.59
= k*c*(.59E9)
= 6.6E-34*3E8(.59E9)
about 1.1E-16 Joule check that math.
the correct answer is 3.375x10^-22 J. But i don't know how to get this answer correctly.
E=planksconstant*(c/lambda)
= k*c (1/589nm -1/589.59nm)
= k*c*(589.59-589)/589*589.59 1/nm
= k*c*( 1.69897351e-6)1E9
= 6.6E-34*3E8( 1.69897351e-6)*1e9
3.3639675e-22