In the Dhanuggaha Sutta, in referring to an individual lifetime, the Buddha said “faster than the speed of the devas who rush ahead of the sun and moon, the force of one’s life span comes to an end”. In the Abidhamma, it is said that the most fundamental unit, the smallest ever that is found survives only 17 mind moments (citta kshana). One mind/thought-moment (cittakshana) is so short that it has been estimated that there are approximately 8,125 moments in a second. Distinguishing these cittakshana is harder than identifying cetasika.
In the Milindapañha it is said that, "If a man were to take a handful of water from the ocean and tasting it could say, ‘This water is from the Ganges, this from the Jumna, this from the Gandak, this from the Sarabhu, and this from the Mahi.’ More difficult than this is the distinguishing of those mental states that accompany any one of the senses."
As it is said in Abidhamma, the smallest particle lives only 17 mind moments, but it still consists of the 8 dhatu: Apo (Liquidity), Thejo (Heat), Wayo (Air), Patavi (Solidness), Warna (Color), Gandha (Smell), Rasa (Taste) and Ojasa (juice). Only a Buddha could see to such a level of detail, and see through the minute subatomic particles which are continuously arising and vanishing.