energy, photon?

Question

Suppose all the energy from a 100 watt light bulb came in the form of photons with wavelength of 600 nm.

a. Calculate the energy of a single photon with wavelengh 600 nm.

b. How many 600 nm photons must be emitted each second to account for

all the light from this 100 watt light bulb?

Answer 1

How can a Photon be a particle and a wave
A wave is a wave it is a pulse in which the individuals particles remain in place , (water wave, sound wave)
A single photon traveling from a light source is a wave not an actual particle, like a baseball in motion.
It only seems correct
Therefore light to propagate as a wave must be traveling through a medium of some type, after all light waves travel from a source in all directions and behave exactly like waves,
The wave length must be larger than the particle size of the medium through which it travels

Water sound wave water molecule

Answer 2

The work function energy WE is the amount of binding energy the photon must overcome to knock an electron out of its orbital. So, theoretically, if the energy of the photon TE = hf = WE, all its energy would be expended getting the electron away from its atom. But there would be none left over for the electron to have kinetic energy. Only if TE > WE, so that TE - WE = KE > 0 is there sufficient left over energy from the photon's energy to propel the electron and give it kinetic energy. The conservation of energy is another way to look at it. When the total energy input is that of the photon we have TE = WE + KE where this RHS is the work and kinetic energies, which, because of the conservation law, must add up to the total energy input by the photon.

Answer 3

For the Energy of a photon we use-:

E = h c / lambda

E = (6.63 x 10^-34) x (3 x 10^8) / (600 x 10^-9)

E = 3.315 x 10^-19 Joules

Now 1 Watt = 1 Joule per second
So 100 Watts is 100 Joules per Second.

Therefore-:

No. of Photons per second = Total Wattage / Energy of 1 Photon

No. of Photons per second = 100 / 3.315 x 10^-19

No. of Photons per second = 3.017 x 10^20 Photons