Is energy conserved when an electron emits a photon of light?

An atom can absorb or emit one photon when an electron makes a transition from one stationary state, or energy level, to another. Conservation of energy determines the energy of the photon and thus the frequency of the emitted or absorbed light.

What is conserved when a photon collides with an electron?

As always in a collision situation, momentum is conserved. In a collision like this, involving a photon and an electron, there is nothing to transfer energy out of the system, so energy is also conserved.

What happens to an electron if it absorbs a photon of sufficient energy?

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.

Is photon number conserved?

However the number of photons is not conserved. Photons are bosons and they are their own antiparticle so no particle number conservation law is violated when you create a photon.

How is energy conserved when atom emits a photon?

So, if an electron moves down from the 2nd energy level to the 1st (n=2 to n=1), then the atom conserves energy by emitting a photon of light. The emitted photon has an energy equal to the difference between the 2nd and 1st energy levels.

When a photon and a free electron collide there is conservation of?

Some of the energy and momentum is transferred to the electron (this is known as the Compton effect), but both energy and momentum are conserved in this elastic collision. After the collision the photon has energy hf/ and the electron has acquired a kinetic energy K.

What happens when a photon is absorbed?

The simplest answer is that when a photon is absorbed by an electron, it is completely destroyed. All its energy is imparted to the electron, which instantly jumps to a new energy level. The photon itself ceases to be. The opposite happens when an electron emits a photon.

Why number of photons is not conserved?

we know electrons gets exited upon interaction with energy . here when they collide with photons(energy packets) they get exited hence the energy is used thus the number of photons are not conserved upon collision with electrons.

Why do photons have momentum?

Note: Rest mass of photon is zero, whenever it starts moving with velocity C, it gains mass according to E= mc^2. Energy of moving particle converted into mass. That’s why its has momentum (when it start moving). Originally Answered: Photons are massless particles.