Answer
Aluminum
Work Step by Step
The electron configuration for the element in the third period with three valance electrons is $[Ne]:3s^{2}3p^{1}$, which corresponds to the element Aluminium.
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.