Answer
Strontium loses two electrons when it forms an ion.
Work Step by Step
Strontium is in group 2 and has two valence electrons. It must lose these two in order to achieve noble gas configuration.
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.