B. Experiments Supporting Particle Theory of Light (20th century)

 

 

 

 

Experiment in the late 1800's baffles scientists.

 

 


 

Light is not acting like a wave!

 

 

 

 

 

 

 

 

Experiment scientists
 can't explain is called…

 

Photoelectric Effect

 

 

 

St. Mary's HS Physics

| Larger |

 

 

 


- when light is exposed
to the surface
of certain metals,
 the light energy is absorbed and electrons
 are ejected



 

 

Light
(or other electromagnetic radiation)

Emitted electrons are called PHOTOELECTRONS

Photosensitive metal

 


 

 

 

 

The light’s energy causes
 the emission of electrons