Editing Metallic bonding (section)

==Strength of the bond==
The atoms in metals have a strong attractive force between them. Much energy is required to overcome it. Therefore, metals often have high boiling points, with [[tungsten]] (5828&nbsp;K) being extremely high. A remarkable exception is the elements of the [[Group 12 element|zinc group]]: Zn, Cd, and Hg. Their electron configurations end in ...n'''s'''<sup>2</sup>, which resembles a noble gas configuration, like that of [[helium]], more and more when going down the periodic table, because the energy differential to the empty n'''p''' orbitals becomes larger. These metals are therefore relatively volatile, and are avoided in [[ultra-high vacuum]] systems.

Otherwise, metallic bonding can be very strong, even in molten metals, such as [[gallium]]. Even though gallium will melt from the heat of one's hand just above room temperature, its boiling point is not far from that of copper. Molten gallium is, therefore, a very nonvolatile liquid, thanks to its strong metallic bonding.

The strong bonding of metals in liquid form demonstrates that the energy of a metallic bond is not highly dependent on the direction of the bond; this lack of bond directionality is a direct consequence of electron delocalization, and is best understood in contrast to the directional bonding of covalent bonds. The energy of a metallic bond is thus mostly a function of the number of electrons which surround the metallic atom, as exemplified by the [[embedded atom model]].<ref>{{cite journal|title=The embedded-atom method: a review of theory and applications|journal=Materials Science Reports|date=1993|volume=9|issue=7–8|pages=251–310|doi=10.1016/0920-2307(93)90001-U|author1-link=Murray S. Daw|author2-link=Stephen M. Foiles|author3-link=Michael Baskes|last1=Daw|first1=Murray S.|last2=Foiles|first2=Stephen M.|last3=Baskes|first3=Michael I.|url=https://zenodo.org/record/1258631|type=Submitted manuscript|doi-access=free}}</ref> This typically results in metals assuming relatively simple, [[Atomic packing factor|close-packed]] crystal structures, such as FCC, BCC, and HCP.

Given high enough cooling rates and appropriate alloy composition, metallic bonding can occur even in [[metallic glass|glasses]], which have amorphous structures.

Much biochemistry is mediated by the weak interaction of metal ions and biomolecules. Such interactions, and their associated [[conformational change]]s, have been measured using [[dual polarisation interferometry]].