Nuclear hypothesis, antiquated philosophical hypothesis that all things can be represented by endless mixes of hard, little, inseparable particles (called molecules) of different sizes however of a similar essential material; or the cutting edge logical hypothesis of issue as per which the synthetic components that consolidate to shape the extraordinary assortment of substances comprise themselves of collections of comparable subunits (iotas) having atomic and electron foundation normal for every component. The antiquated nuclear hypothesis was proposed in the fifth century BC by the Greek rationalists Leucippus and Democritus and was restored in the first century BC by the Roman savant