A metallic bond is the sharing of many detached electrons between many positive ions, where the electrons act as a "glue" giving the substance a definite structure. It is unlike covalent or ionic bonding. Metals have low ionization energy. Therefore, the valence electrons can be delocalized throughout the metals. Yes, it has a higher ionization energy. Cations are also smaller than the neutral atom, and the reason for both is the same.
Many people have had strong shocks from the electric wires in a house. The wires seldom carry current at a higher voltage than 220, and a person who touches It is easy for us to see how we can reduce resistance: it is necessary to make use of a better conducting material and as thick wires as possible.
8. A high ionization-energy value indicates that the atom has a strong hold on its electrons and is not likely to lose an outer electron and form a positive ion. 9. The first ionization energies generally increase as you move left-to-right across a period. The increased nuclear charge of each successive element produces an increased hold on the valence electrons. 10. The first ionization energies generally decrease as you move down a group.