Terbium

 Terbium : Recently, scientists at the Indian Institute of Science (IISc) developed a glowing paper sensor that uses terbium, to enable the early detection of liver cancer. The sensor emits a green glow, providing a simple and visual method for diagnosis.

• About Terbium: A rare-earth metal belonging to the lanthanide series of the periodic table.

o Sources: Found in rare-earth minerals such as bastnasite, extracted from ion-exchange clays (laterites) and also produced as a byproduct of nuclear fission.

• Properties : A moderately hard, silvery-white metal. It forms a protective oxide layer (Tb₂O₃ and TbO₂), which keeps it stable even at high temperatures.

o Terbium reacts easily with diluted acids. It is insoluble in hydrofluoric acid (HF) because it forms a protective TbF₃ layer that prevents further reaction.

• Uses of Terbium: Display Technology: Used in green phosphors for fluorescent lamps, TVs, and computer monitors (especially CRTs).

o Magnetostrictive Alloys: Combined with dysprosium and iron to form Terfenol-D, a material that converts magnetic energy into mechanical motion, useful in sonar, sensors, and actuators.