Metallic Bonds

Electron Sea Model Metals often form lattices in the solid state. In these lattices, 8-12 other metal atoms surround each metal atom. In these crowded conditions, the outer energy levels of the metal overlap. Metal atoms contribute their valence electrons to form a “sea” of electrons. Electrons in this “sea” are referred to as delocalized electrons Each metallic cation is bonded to all neighboring metal cations by the delocalized electrons forming a metallic bond.

Properties of Metals Melting and Boiling Points Metals have much higher boiling points than melting points, because the atoms don’t mind moving past each other, but they do not want to separate from the sea of delocalized electrons. Melting and boiling points of metals become higher as the amount of delocalized electrons increases Valence electrons and unpaired d electrons contribute to the sea of delocalized electrons.

Properties of Metals Malleable and Ductile Metal cations have no problem moving past each other if enough external force is applied.

Properties of Metals Good Conductors of Heat and Electricity The movement of delocalized electrons throughout the metal, move heat from one place to another. An electrical current is created by the movement of electrons Delocalized electrons are able to move freely, and therefore, easily move as part of an electric current when electrical potential is applied to the metal.

Metal Alloys An Alloy is a mixture of elements that has metallic properties. The properties of alloys differ somewhat from the properties of the elements they contain. E.g. steel is iron mixed with another element. Some properties of iron are present, but steel has additional properties, such as increased strength.