Answer
$X_{2}Y$
Work Step by Step
Since valency of X ion is +1 and Y ion is -2, so 2 atoms of element X are required to balance 2 electrons of element Y.
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.