You are confronted with an unknown metal, M, and need to determine its identity. Using the following information identify the metal.
M(s) Reacts vigorously with water and acid.
M(s) does not react with K+(aq)
M(s) reacts with Co+2(aq)
M(s) does not react with Ca+2(s)
M(s) reacts with Na+(aq)