noun
Scientific term referring to the theory that matter is composed of atoms. Used in physics and chemistry contexts.
原子説は古代ギリシャにまでさかのぼる。
Atomic theory dates back to ancient Greece.
ドルトンの原子説は化学の基礎となった。
Dalton's atomic theory became the foundation of chemistry.
Compound of 原子 (atom) and 説 (theory).