when you crumble paper is still paper when you burn down paper you get ashes. that is want is call chemical and physical changes.
metal have free electrons in their outer shell which make them generally good conductors of electricity. Example is the copper which is used for electrical wiring since is a good conductor of electricity. copper with electronic configuration of (Ar)4s2 has two free electrons in their outer most shell which allow it to conduct electricity.
26Fe59 ----> -1e0 + 27Co59
Solidity, solidness, denseness, thickness, substance, mass......
