d block

The d-block elements begin with the fourth-period rare-earth metal scandium, which represents the first instance of a partially filled d-electron shell, and includes the metals of groups 4 through 12, as well as scandium's group 3 homologs yttrium, lanthanum, and actinium. All are metals and react by losing electrons; all tend to form brightly colored compounds and show a wide range of oxidation states; and all exhibit either ferromagnetism or paramagnetism. With the exception of the denser elements of the zinc group, all have high boiling and melting points. (The rare earths cerium, gadolinium, and lutetium, all members of the f-block group, each have a single d electron, as do the actinons protactinium, uranium, neptunium, curium, and lawrencium. The actinon thorium has two d electrons and no f electrons. Despite these unusual configurations, the foregoing are considered f-block elements.)