The melting point of transition elements increases to a maximum at d5 and decreases with the increase of atomic number across a period.
- The transition metals are characterized by partially filled d & subshells in the free elements and cations.
- The ns and (n − 1) d subshells have similar energies, so small influences can produce electron configurations that do not conform to the general order in which the subshells are filled.
- The group 4 metals become denser, higher melting, and more electropositive down the column.
- The trends in boiling and melting points vary from group to group, based on non-bonding interactions holding the atoms together.
