A longstanding mystery of the periodic table involves a group of unique elements called lanthanides. Also known as rare earth elements, or REEs, these silvery-white metals are challenging to isolate, given their very similar chemical and physical properties. This similarity makes it difficult to distinguish REEs from one another during extraction and purification processes.
The world has come to depend on lanthanides' magnetic and optical properties to drive much of modern technology—from medical imaging to missiles to smartphones. These metals are also in short supply, and because they're found in minerals, lanthanides are difficult to mine and separate. But that may change—thanks to a Georgia Tech-led discovery of a new oxidation state for a lanthanide element known as praseodymium.
For the first time ever, praseodymium achieved a 5+ oxidation state. Oxidation occurs when a substance meets oxygen or another oxidizing substance. (The browning on the flesh of a cut apple, as well as rust on metal, are examples of oxidation.)