Question

A heat lamp produces 21.0 watts of power at a wavelength of 6.3 μm. How many photons are emitted per second? (1 W = 1 J/s)
a) 3.16 × 10¹⁹ photons/s
b) 5.27 × 10¹⁹ photons/s
c) 7.22 × 10¹⁹ photons/s
d) 9.41 × 10¹⁹ photons/s