The buildings in this old mine are made of metal. you can see over 100 years, the silver color of the buildings has changed. the red-brown color is rust. what does this color change tell us about the metal? a) the metal is malleable. b) the metal reacts in the presence of air and water. c) acid rain has damaged the building over the years. d) the metal is a good conductor of heat and electricity.

ca has a crystalline lattice with positive ions (since it is a metal, metals are positively charged) and electrons flow freely in its structure since the ca atoms have a large nuclear radius so the electrons are not tightly held, therefore the electrons can flow freely since they are not being highly attracted by the nucleus. moreover, one of the properties of metals are that they are conductors of electricity, thus proving ca is the element.