It has been suggested that a fundamental physical unit of time is the time required for light to traverse the diameter of the nucleus of an atom (approximately 3 $\times$ 10^-13 m).This unit of time is approximately A)1 s B)10^-4 s C)2 $\times$ 10^-20 s D)10^-21 s E)10^-23 s

Question

Quizplus · Accepted Answer

The time required for light to traverse the diameter of the nucleus of an atom is approximately 3.3 × 10^-23 seconds. Therefore, the correct choice is D, which is 10^-21 seconds or 0.1 nanoseconds. Choice A is too large, choices B and C are too small, and choice E is much too small.

It Has Been Suggested That a Fundamental Physical Unit of Time