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Dubnium

physical science Maturity 11-13 Next article →

Dubnium is a man-made chemical element. It has the symbol Db and the atomic number 105. You cannot find this element naturally on Earth. Scientists must create it through a process called synthesis. This means they build it in a laboratory.

Transactinide chemistry apparatus Dubna
Transactinide chemistry apparatus Dubna

Dubnium is a highly radioactive element. This means it is unstable and breaks down very quickly. The most stable version is called dubnium-268. This version has a half-life of about 16 hours. A half-life is the time it takes for half of a sample to decay. Because it disappears so fast, it is very hard to study for a long time.

Nucleus half life and decay
Nucleus half life and decay

To make dubnium, scientists must crash atoms together. In 1968, researchers in the Soviet Union used a beam of neon ions. They aimed these ions at a target made of americium-243. This collision created the element. In 1970, a team in California tried a different way. They bombarded californium-249 with nitrogen-15 ions. Both teams saw the new element appear through its energy signatures. These tiny collisions allow us to build things that do not exist in nature.

Radiochem 104+ Transactinide
Radiochem 104+ Transactinide

The discovery of dubnium led to a long argument. This period was called the Transfermium Wars. The Soviet Joint Institute for Nuclear Research claimed they found it in 1968. The American Lawrence Berkeley Laboratory claimed they found it in 1970. Each team wanted to name the element themselves. The Soviet team suggested names like bohrium or nielsbohrium. The American team suggested the name hahnium. This rivalry lasted for many years.

Atomic orbitals dubnium
Atomic orbitals dubnium

In 1993, a group called the Transfermium Working Group solved the dispute. They looked at all the evidence from both sides. They decided that both teams should share the credit for the discovery. In 1997, the element was officially named dubnium. This name honors the town of Dubna in Russia. This is where the Soviet research institute is located. This name helped end the many years of naming disagreements.

7s electrons dubnium relativistic vs nonrelativistic
7s electrons dubnium relativistic vs nonrelativistic

Scientists study where dubnium fits on the periodic table. It belongs to group 5 of the transition metals. This means it sits in a line with vanadium, niobium, and tantalum. It should act like these other metals in many ways. However, it has some strange differences. These differences happen because of relativistic effects. These effects change how the electrons move around the center of the atom. Understanding these small changes helps us learn how the universe works.

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🖼️ Images & Media (5)
File:Transactinide chemistry apparatus Dubna.jpg
Transactinide chemistry apparatus Dubna.jpg
File:Nucleus half life and decay.svg
Nucleus half life and decay.svg
File:7s electrons dubnium relativistic vs nonrelativistic.svg
7s electrons dubnium relativistic vs...
File:Atomic orbitals dubnium.svg
Atomic orbitals dubnium.svg
File:Radiochem 104+ Transactinide.svg
Radiochem 104+ Transactinide.svg
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