1 E-21 s

Template:Associations/Orders of magnitude (time) To help compare orders of magnitude of different times this page lists times between 10⁻²¹ seconds and 10⁻¹⁸ seconds (1 zeptosecond and 1 attosecond). See also times of other orders of magnitude.

• shorter times
• 7 zs, half-life of helium-9's outer neutron in the second nuclear halo
• about 17 zs, the approximate period of electromagnetic radiation at the boundary between gamma rays and X-rays
• about 300 zs, typical cycle time of X-rays, on the boundary between hard and soft X-rays
• longer times