Answer:
The energy of a photon can be determined from it's wavelength, or frequency, with the use of Planck's constant, a physical constant that relates frequency and energy of a photon. This photon, with a wavelenght of 6.4x10^-7 m has an energy of 3.1x10^-19 Joules.
Step-by-step explanation:
The energy of a photon is given by:
Energy = Frequency*(Plank's Constant)
Planck's constant `is a is a conversion factor that relates the energy of a photon and the photo's frequency. It is 6.626x10^-34 J*s.
Frequency can be calculated from a photo's wavelength with:
Speed = (Wavelength)*(Frequency), or S = W*F
For a photon, the speed is the speed of light, 3.0x10^8 m/sec.
To find frequency for this photon:
S = W*F
F = S/W
F = (3.0x10^8 m/sec)/(6.4 x 10^-7 m)
F = 4.69x10^14 Hertz [(s^-1)]
The energy is:
Energy = Frequency*(Plank's Constant)
Energy = (4.69x10^14/s)(6.626x10^-34 J*s)
Energy = 3.1 x 10^-19 Joules