Metals: bonding, reactivity, alloys, and extraction
A metal's position in the electrochemical series links microscopic electron behavior to displacement reactions, corrosion, and the energy needed to obtain the metal.
1. Metallic bonding and alloys
Metallic structure
Metal atoms contribute valence electrons to a delocalized electron system surrounding positive metal-ion cores. Nondirectional attraction holds the lattice together. Mobile electrons explain electrical and thermal conductivity; layers of ions can shift while bonding persists, explaining malleability and ductility.
Alloys
An alloy is a metallic material containing at least one metal and one or more additional elements. Similar-sized atoms can substitute in lattice sites; smaller atoms can occupy interstices. The disturbed lattice often raises hardness and strength but may lower ductility or conductivity. Alloy composition is a controlled range, not necessarily a fixed compound formula.
2. Electrochemical series as a prediction tool
For the reduction half-reaction Mn+ + ne− → M, a more negative standard reduction potential E° means the metal is more readily oxidized and is usually a stronger reducing agent. A metal higher in a simplified activity series can displace ions of a less reactive metal from solution when conditions are suitable.