I believe you have to label out the positive metal ion and the delocalized electrons. They're the 2 things that makes up a metal structure.
In the diagram, the circles with the + symbol are the positive metal ions, since + represents positive. And the remaining - circles are the delocalized electrons, as electrons are negative.
And for how a metal conducts electricity, since they're delocalized mobile electrons present in any metal structures, they're able to move away from the metal to the positive side of the battery and more electrons can replace their place flowing from the negative side.
A covalent bond is your answer
Adding perchloric acid to water would cause it's conductivity to increase.
This is true. Elements past lead are radioactive, because the repulsive force of the protons cannot be overpowered by the “gluing” ability of neutrons (remember, likes repel). As more and more protons are added, generally, the elements become more unstable; for example, Bismuth, right next to lead on the Periodic Table, is radioactive, but the half life of this element is about a billion times longer than the current age of the universe, but Oganesson, element number 118, has a half life of fractions of a second.
2Na + 2H2O ——> 2 NaOH + H2