This question already has an answer here:

Many metals form compounds with s-block elements that are essentially entirely ionic. However, elements like silver, copper, lithium and so on, can form bonds that are significantly covalent in character. What are the factors that govern whether a particular metal will bond with significant covalent character? Is this linked to hardness and softness?


marked as duplicate by jerepierre, ron, user467, M.A.R., Curt F. Apr 14 '15 at 0:54

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.