Answer
Ru has the highest melting point.
Work Step by Step
As the number of valence electrons increases, so does the strength of the metal bond. Ru has 8 valence electrons, which is more than any other in the group.
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.