Quanta

Planck developed an equation for black body radiation by hypothesizing that energy is emitted in discrete pieces called quanta. This discovery introduced the concept of energy quantization, laying the foundation for quantum mechanics.
 Max Karl Ernst Ludwig Planck Germany 1900 Quanta

Planck developed an equation for black body radiation by hypothesizing that energy is emitted in discrete pieces called quanta. This discovery introduced the concept of energy quantization, laying the foundation for quantum mechanics.