Terbium is the sixty fifth element on the periodic table, giving it sixty five protons and electrons. Never found in nature as a free element, terbium can instead be found in minerals such as cerite, gadolinite, monazite, xenotime and euxenite.
The element is typically characterized as a transition metal, or sometimes as an inner transition metal. Given the sheer number of transition metals it is difficult to define any definite characteristics but, generally, transition metals are paramagnetic with more than one oxidation states. Also, metals typically (though not always) have high electrical conductivity as well as high density and high melting and boiling points.
Within the transition metals, terbium is classified as a lanthanide. All lanthanides are considered rare earth elements on the periodic table. Despite the name however, rare earth elements are not necessarily rare – they’re just notoriously hard to find in large enough quantities to be useful. Often found together, rare earth elements are difficult to separate.
A soft, silvery-white, ductile and malleable metal, terbium has two major allotropes with a transformation temperature at 1289 °C. Naturally occurring terbium has only one stable isotope, making the element both mononuclidic and monoisotopic.
Комментариев нет:
Отправить комментарий