Lanthanides elements with atomic numbers 58-71 may although there are some disputes over exactly where the lanthanides begin and end. This element series is the group of elements in which the 4f sublevel is being filled. See the section on lanthanides for more and more information.
Lanthanides posses common properties like silvery-white metals that tarnish when exposed to air, forming their oxides. Shifting from left to right across the period (increasing atomic number), the radius of each lanthanide 3+ ion gradually decreases. In general this element has high melting points and boiling points. It also reacts with water to liberate hydrogen (H2), gradually in cold/quickly upon heating.Lanthanides react with H+ to release H2 i.e. rapidly at room temperature and also react in an exothermic reaction with H2. It will burn easily in air also has strong reducing agents. Their compounds are usually ionic. The majority rare earth compounds are robustly paramagnetic and more rare earth compounds fluoresce strongly under the ultraviolet light.