Answer:
"Mentals"? I think you mean "Metals". There are several useful properties in metals. Its hardness and density are useful in building and constructing. Its smooth nonporous surface is useful in many different ways, its flexibility and endurance are great for making earth quake proof buildings and bridges.Look at the San Francisco bridge. Exponentially, there are no limit to the useful properties of metal. All you have to do is look it up.