A Sodium Vapor Lamp Has a Power Output of 60

Multiple Choice

A sodium vapor lamp has a power output of 60 W.If 547 nm is the average wavelength of the source,about how many photons are emitted per second? (h = 6.63 × 10−³⁴ J⋅s,c = 3.00 × 10⁸ m/s,and 1 nm = 10−⁹ m)

A) 10¹⁸
B) 10²⁰
C) 10³⁹
D) 10²⁹
E) ​10²⁸