Answer:
The frequency of an electromagnetic wave with energy 5.0 *10^-20 J is 7.55 * 10^13 Hz (option A)
Step-by-step explanation:
Step 1: Data given
Energy = 5.0 *10^-20 J
Planck's cosntant = 6.626* 10^-34 m²kg/s
Step 2: Calculate the frequency
E = h*f
⇒ with E = the energy in joules = 5.0 * 10^-20 J
⇒ with h = Planck's constant = 6.626* 10^-34 m²kg/s
⇒ with f = the frequency (in Hz)
f = E/h
f = 5.0 * 10^-20 J/6.626* 10^-34 m²kg/s
f = 7.55 * 10^13 Hz
The frequency of an electromagnetic wave with energy 5.0 *10^-20 J is 7.55 * 10^13 Hz (option A)