In a Vacuum

[Sameer Chowdhury 3C]

In order for the photoelectric effect experiment to be done correctly, one of the conditions was that it needs to occur within a vacuum. What specifically happens if that isn't the case. I understand that the electrons will interact with air molecules. Do these interactions simply pull the electrons away from the direction of the electron detector?

[Katie Nye 2F]

To my understanding, if the electrons are interacting with the molecules in the air we wouldn't get an accurate representation of how the electrons react with the light. We can't get an accurate velocity of the escaping electrons because they're colliding with what's already in the air. It keeps the experiment controlled.

[Jason Nguyen_1B]

Also, I believe that once electrons are ejected, they can interact and collide with air molecules, causing the electrons to lose energy. Thus, when the electrons do reach the electron detector, they will have lower energies then they should resulting in inaccurate data.

[Lily Mohtashami]

Using a vacuum controls the experiment so that you know anything that is observed is based completely on the light and the electrons and is not affected by any other particles. These particles could simply collide with the electrons and change the speed which alters the results of the experiment.

[Muskaan Abdul-Sattar]

To my understanding, without the vacuum, the particles would not be controlled and collide with the electrons.

[Lillian]

In addition to offsetting the electron's velocity, it could also interact as in bind with the electron, absorb the energy of the electron, pull it in its direction, etc. It would directly affect the experiment's results.

[Emma Strassner 1J]

I agree, using a vacuum is necessary in this case because without a vacuum, collisions with the air molecules cause them to lose energy before reaching the detector. In order for the detector to obtain the correct readings, the vacuum is needed to reduce electron collisions and keep the maximum energy they have.

[Griffin G]

The vacuum is only necessary to remove as many variables from an experiment as possible. If electrons interacted with molecules in the air, they would lose energy, bounce in different directions, etc. That is to say - a vacuum is used to collect the most accurate scientific data possible, the photoelectric effect still occurs in nature regardless as to whether or not electrons are moving through a vacuum or not.