contestada

What is the energy of a wave with wavelength of 4.2 x 10-7 m. (Hint: Calculate for frequency first.)
A. 4.74 x 10-28 Joules
B. 4.74 x 10-19 Joules
C. 8.35 x 10-32 Joules
D. 2.79 x 10-40 Joules