What are the three main factors that affect metallic bonding?

A metallic bond is the electrostatic force of attraction between the positive metals ions and the delocalised electrons. The three main factors that affect the strength of a metallic bond are: the number of protons (the more protons the more stronger the bond); number of delocalised electrons per atom ( the more the stronger the bond); the size of the ion (the SMALLER the ion, the stronger the bond).