What happens to the excess energy of the photon?

Photon energy in excess of this amount, when pair production occurs, is converted into motion of the electron-positron pair. The positron that is formed quickly disappears by reconversion into photons in the process of annihilation with another electron in matter.

Why is the energy of a photon greater than rest mass energy?

The frequency of the light detected was higher than the light emitted. This result confirms that the energy of photons increases when they fall in the gravitational field of the Earth. The energy, and therefore the gravitational mass, of photons is proportional to their frequency as stated by the Planck’s relation.

Is the energy of a photon related to its mass?

Sometimes people like to say that the photon does have mass because a photon has energy E = hf where h is Planck’s constant and f is the frequency of the photon. Energy, they say, is equivalent to mass according to Einstein’s famous formula E = mc2.

What is the highest energy a photon can have?

gamma rays
A collaboration of Chinese and Japanese astrophysicists has reported the highest energy photons ever seen: gamma rays with energies up to 450 trillion electron volts (TeV).

What happens to the extra energy?

“The extra energy is stored in adipose tissue all around your body in the form of triglycerides,” says Dr. Burguera. Smaller amounts of energy are stored in your liver and muscles as glycogen.

What happens when a photon hits an electron?

When an electron is hit by a photon of light, it absorbs the quanta of energy the photon was carrying and moves to a higher energy state. Electrons therefore have to jump around within the atom as they either gain or lose energy.

What is the momentum of a photon whose energy is equal to the rest mass energy of the electron?

2. 7×10−22kgms−1.

What if photons have mass?

The speed of light is special: nothing with mass can move at that speed, or accelerate to it. If photons have mass, then obviously the “speed of light” becomes a misnomer. Massless particles would still travel at that speed — if any particles end up being massless after the carnage is done.

How much energy does a photon have?

The energy of a single photon is: hν or = (h/2π)ω where h is Planck’s constant: 6.626 x 10-34 Joule-sec. One photon of visible light contains about 10-19 Joules (not much!) the number of photons per second in a beam.

What happens if the photon energy is less than the work function?

If the photon energy is less than the work function, no electrons are emitted. The cutoff frequency fois where the photon energy hfo= Wo Above the cutoff frequency the photons have more energy than what is needed to eject an electron.

What is the relationship between photon energy and electron kinetic energy?

If the photon energy is less than the work function, no electrons are emitted. The cutoff frequency f o is where the photon energy hf o = W o. Above the cutoff frequency the photons have more energy than what is needed to eject an electron. The extra energy shows up as the electron’s kinetic energy:

What happens to an electron when a photon hits a metal?

If this photon has enough energy, the electron is freed. Excess energy appears as kinetic energy of the electron. The maximum kinetic energy of the electron is given by E=hf – Φ. If the photon does not have enough energy, then the electron cannot escape the metal.

What are the characteristics of photons?

• Photons travel some considerable distance before undergoing a more. “catastrophic” interaction leading to partial or total transfer of the photon energy to electron energy. • These electrons will ultimately deposit their energy in the medium. • Photons are far more penetrating than charged particles of similar energy.