atomic theory

Noun

• (chemistry) any theory in which all matter is composed of tiny discrete finite indivisible indestructible particles
  • the ancient Greek philosophers Democritus and Epicurus held atomic theories of the universe
    

• a theory of the structure of the atom

Related words

• Synonyms: 
  atomism , atomist theory , atomistic theory
• Antonyms: 
  holism , holistic theory