Answer
$\Delta_n = 0.008665~u$
Work Step by Step
We can find the mass excess of a neutron:
$\Delta_n = M - A$
$\Delta_n = 1.008665~u - 1~u$
$\Delta_n = 0.008665~u$
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.