röntgeni

Röntgeni, or roentgenium, is a synthetic chemical element with the symbol Rg and atomic number 111. It is the heaviest element whose existence has been confirmed and is placed in group 11 of the periodic table, where it is expected to share some chemistry with copper, silver, and gold. The name honors Wilhelm Conrad Röntgen, the discoverer of X-rays; the name was approved by IUPAC in 2004.

Röntgenium is produced only in particle accelerators through fusion reactions that combine heavy target nuclei with lighter projectile ions. It has no natural occurrence and exists only for fractions of a second to minutes in laboratory conditions, making observations extremely challenging.

All isotopes of roentgenium are radioactive and highly unstable. The known isotopes have very short half-lives, typically ranging from milliseconds to minutes, which limits experimental work and prevents practical applications outside fundamental research.

Chemistry and physics studies of roentgenium focus on its place in the periodic table and the influence of relativistic effects on the behavior of superheavy elements. Early experiments aim to observe whether roentgenium behaves like other coinage metals, but results are limited by the tiny amounts produced and short lifetimes. The element is primarily of interest to researchers studying nuclear stability, atomic theory, and the chemistry of the heaviest elements.

In summary, roentgenium is a laboratory-created, highly radioactive superheavy element with no practical applications, studied to better understand the limits of the periodic table.

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