Term

Definition
The fundamental "size" unit; the smallest amount of anything. One quantum of light energy is called a photon. 


Term

Definition
In the particle model of electromagnetic radiation, a particle that travels only at the speed of light and whose energy is related to the frequency of the radiation in the wave model. 


Term

Definition
A fundamental constant of quantum theory that determines the scale of the smallscale world. Planck's constant (symbol h) multiplied by the frequency of radiation gives the energy of a photon of that radiation. 


Term

Definition
The ejection of electrons from certain metals when eposed to certain frequencies of light. 


Term

Definition
The branch of physics that is the study of the motion of particles in the micro world of atoms and nuclei. 


Term

Definition
The branch of physics that is the general study of the micro world of photons, atoms, and nuclei. 

