Answer :
Answer: D. [tex]5.0(10)^{-38} J[/tex]
Explanation:
The energy [tex]E[/tex] of an electromagmetic wave is given by:
[tex]E=\frac{hc}{\lambda}[/tex]
Where:
[tex]h=6.626(10)^{-34}J.s[/tex] is the Planck constant
[tex]c=3(10)^{8} m/s[/tex] is the speed of light in vacuum
Then [tex]hc=1.99 (10)^{-25}Jm[/tex]
[tex]\lambda=4.0(10)^{12} m[/tex] is the wavelength
Solving:
[tex]E=\frac{1.99 (10)^{-25}Jm}{4.0(10)^{12} m}[/tex]
[tex]E=5.0(10)^{-38} J[/tex]