## Chemistry: A Molecular Approach (3rd Edition)

$556.2\times10^{-3}femtoseconds$
We get this answer because the relationship between seconds and femtoseconds is 10$^{15}$. So, there are 1 000 000 000 000 000 femtoseconds in one second. We multiply our original by 10$^{15}$ to get our answer.