Since ancient times, scientists have been probing matter to discover its structure and building blocks. Early on scientists thought that the natural world was built from molecules. Then they found that molecules were built from atoms, which were later determined to be composed of subatomic particles, such as protons, neutrons and electrons.
自古，科學家即不斷探究物質的組成與構造，如眾所周知，早年，自然界的物體曾被認為由分子構成；後來發現分子又由原子構成；之後更進一步解析出原子內還包含了質子、中子及電子。