Melting of ice is endothermic because it is taking heat from the environment, feeling cold, because it requires energy to break the ice bonds. It's also why you feel cold when wet it takes energy to evaporate water. The ice absorbs the energy from the environment. Its internal potential energy increases, therefore, it's endothermic. It also increases the entropy of reaction.
A simple explanation of what alloys are and how they're made, with a table ... That's why most of the "metals" we use are not actually metals at all but alloys
