Final answer:
A discrete amount of energy is called a quantum. Energy is quantized in some systems, meaning that the system can have only certain energies and not a continuum of energies. This concept was first introduced by Max Planck, who showed that energy could be lost or gained by an atom in small discrete units called quanta.
Step-by-step explanation:
A discrete amount of energy is called a quantum. Energy is quantized in some systems, meaning that the system can have only certain energies and not a continuum of energies. This concept was first introduced by Max Planck, who showed that energy could be lost or gained by an atom in small discrete units called quanta.