Metals non-metals and metaloids
By Ethan Cain
Platinum is very luster (shiny) like most metals but has a rarer trait than most metals, being both malleable (can be flattened out) and ductile (can be made into thin wires.) So if platinum was not as rare as it is it could be one of the most useful metals on earth.
The non-metal bromine is not very luster and not very dense. However it might be denser than some other non-metals it is not nearly as dense as a metal. It also has a low melting point so that means the temperature that it melts at is not very high.
Arsenic is a metalloid so it will share traits of metals and non-metals. Arsenic is not very luster but at the same time can be luster. It is also a very dense material. It is also malleable (can be flattened.)