Atomic clocks are the most precise timepieces ever created. To preserve correct time, the clock employs an electronic transition frequency through an atom's electromagnetic spectrum as a frequency reference.
The atomic clock has become so precise that it will not succeed or fail a second in .
Cesium atomic clock:
The most precise form of clock ever created is the cesium atomic clock.
This gadget uses transitions between the spinning states of the cesium nucleus to provide a frequency that is so consistent that it has been utilized to create the time standard.
Therefore, the most accurate atomic clock is the cesium atomic clock.