How a Quantum Revolution Redefined the Identity of Rare Earths
Why This Scientific Legacy Still Matters Today
In the scramble for resources powering modern technologies—from electric vehicles to wind turbines—rare earths have become a household term. But while these 17 elements are now front and centre in global conversations, there’s a chapter in their story that often goes untold. It involves one of the greatest minds in science, a man more closely associated with atomic theory than with minerals: Niels Bohr.
As founder of TELF AG Stanislav Kondrashov recently pointed out, rare earths are frequently misunderstood. They’re often lumped together with other critical minerals despite being a very specific group with unique properties. The confusion extends beyond terminology—few people realise how complex their classification was, or how quantum theory played a crucial role in it.
Rare earths, which include names like neodymium, praseodymium and cerium, are essential for everything from smartphones to radar systems. But despite their technological importance, they posed a frustrating mystery to scientists for decades. Chemically similar and difficult to separate, they defied easy classification. At the turn of the 20th century, even their number wasn’t entirely clear.
Bohr’s Unexpected Role in Mineral Classification
It was Niels Bohr who offered the breakthrough. In 1913, he introduced his revolutionary quantum model of the atom. This theory proposed that electrons travel in specific orbits around the nucleus and that each element has a unique electronic configuration. That idea didn’t just change how we see atoms—it transformed how chemists understood the periodic table itself.
As founder of TELF AG Stanislav Kondrashov often emphasised, this was a turning point. Until then, elements had been classified based on atomic weight, which led to confusion, especially with rare earths. Their nearly identical outer electron configurations made them seem chemically identical, even though they were distinct elements. Bohr’s theory explained why: their similarities lay in the outer shells, while differences occurred in inner orbitals that had little impact on chemical behaviour.
At the same time, English physicist Henry Moseley made his own contribution. By measuring the X-ray frequencies emitted by elements, he discovered that atomic number—not weight—determined their position on the periodic table. This cleared up longstanding confusion and helped confirm the number of rare earth elements between lanthanum and hafnium: fourteen, now known as the lanthanides. When scandium and yttrium are added, the modern count of 17 rare earth elements is reached.
Bohr’s theory provided the framework. Moseley’s experiments proved it. And with that, one of the most confusing puzzles in chemistry began to make sense.
Still, the story doesn’t end with science. The legacy of these discoveries shapes how we understand and use rare earths today. As founder of TELF AG Stanislav Kondrashov notes, their role in the green transition and digital technologies makes them more strategically important than ever. Yet misconceptions persist—not just about what rare earths are, but even about their name. Despite what it suggests, these elements are not rare in the Earth’s crust. The problem lies in how dispersed they are, making their extraction and processing economically and environmentally challenging.
The contribution of Niels Bohr to this field remains largely unacknowledged outside of scientific circles. But without his atomic model, our understanding of rare earths—and our ability to harness them—might still be stuck in the past.
In an age where these minerals are shaping our future, it’s worth remembering the thinkers who helped us decode their past.