Question 2
When the outer electrons leave the atoms in a piece of metal, what is left behind?
The right answer is the one marked above.
Positive metal ions. An atom that has lost electrons has more protons than electrons, so it is left positively charged. These ions stay fixed in place while the electrons move.
This is why no copper travels anywhere in a copper wire carrying a current. Only the electrons move; the lattice of ions stays put.