Given below is a table containing a few metals and non-metals with exceptional properties. Fill the spaces by identifying X, Y, and Z in the table.
Sl.ElementCategoryExceptional Property1.Graphite (C)Non-metalConducts electricity2.Magnesium (Mg)Non-metalHardest natural substance3.Iodine (I)Non-metalZ4.Potassium (K)YSoft (can be cut with knife)5.XMetalLow M.P. (melts in hand)