<h3>the best estimate for earth age is based on radiometric dating of fragment from the canyon dialo iron meteorite from the fragments scientist calculated the relative abundance of element that's for maid as radioactive Uranium decayed over billion of years</h3>
Have you tried the app Socratic it teaches and gives you answers...
The order from the longest to the largest will be; Eon, Era, Period, Epoch.
Eon is the longest division of geologic time. Epoch is the shortest division of geologic time, only present in Cenozoic Era. Era is the second longest division of time, marked by sweeping changes in the fossil record. Period is the time division which is longer than an epoch but shorter than an Era.