Metals are held together by delocalized bonds formed from the atomic orbitals
of all the atoms in the lattice. The orbitals spread over many atoms and
blend into a band of molecular orbitals. The range of energies of these
orbitals are closely spaced. The band is composed of as many levels as
there are contributing atomic orbitals and each level can hold electrons
of opposite spin. The idea that the molecular orbitals of the band of energy
levels are spread or delocalized over the atoms of the piece of metal accounts
for bonding in metallic solids. This theory of metallic bonding is called
the band theory. The band is split into two regions, the upper portion
being the empty levels or the antibonding and the lower portion is the
filled levels or the bonding orbitals. In a metal the band of energy levels
is only partly filled. The highest filled level right before going to the
empty level is called the Fermi level. The trend of melting points of the
transition metals is based on the electrons in the metal.
INSTRUCTIONS:
Select an element to determine the melting point and view the bonding and
antibonding electrons to determine the effect of the electrons on the melting
point.