Terbium is a soft, silvery-white metal that is never found in free form in nature. However, it is found naturally in a number of minerals, along with other rare earth elements, and it is estimated that about 1.2 mg of terbium per kilogram is found in the crust of the Earth. Terbium is a chemical element and is represented by the chemical symbol Tb and the atomic number 65. Terbium has few uses, but is mined in small amounts each year. The largest reserves of the metal are found in Southern China and the most important mineral for the commercial extraction of terbium is bastnäsite (bastnaesite). Let’s find out who discovered this element.
Who discovered terbium?
Terbium was discovered by the Swedish chemist Carl Gustaf Mosander. He was working with the mineral Yttrium oxide (yttria) and discovered terbium in his sample. He named the element after the town of Ytterby in Sweden. Mosander separated yttria into three fractions (he called these yttria, erbia and terbia). Terbium (which was originally called erbia) only made up about 1% of the yttria and many scientists were unable to replicate Mosander’s results. This caused much confusion about the existence of terbium and the names erbia and terbia were mixed up in the process. This means that Mosander discovered both erbium and terbium, but he originally gave them the opposite names! His results were eventually confirmed and he is credited with the discovery. The first isolation of the pure metal did not occur until much later with the invention of ion exchange techniques.
Did you know?
Mosander was taught chemistry by fellow Swedish chemist Jöns Jakob Berzelius. They were both extremely successful in their industry. Berzelius is credited with the discovery of four elements (and played a part in two other discoveries) and Mosander discovered three!