Answer
5.5 x $10^{-9}$
Work Step by Step
This is because for numbers with a negative ten power, larger exponents are smaller. For example, ten to the negative one is .1, while ten to the negative three is .001.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.