roentgenium

American  

[rent-gen-ee-uhm, -jen-, ruhnt-] / rɛntˈgɛn i əm, -ˈdʒɛn-, rʌnt- /

noun

Chemistry, Physics.

1. a superheavy, synthetic radioactive element with a very short half-life. Rg; 111.

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roentgenium Scientific  

/ rĕnt-gĕn′ē-əm,-jĕn′-,rŭnt-,rœnt-gĕn′- /

1. An artificially produced radioactive element with a mass number of 280. Its most stable known isotope has a half-life of 3.6 seconds. Atomic number 111.

2. See Periodic Table

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Etymology

Origin of roentgenium

First recorded in 2000–05; named after German physicist Wilhelm Konrad Roentgen.

Example Sentences

They are Darmstadtium, or Ds, which has 110 protons in its nucleus and was named after the town in which it was discovered; Roentgenium, or Rg, with 111 protons, named after the discoverer of X-rays Wilhelm Conrad Roentgen; and Copernicium, or Cn, which has 112 protons and is named after the Polish astronomer Copernicus, who disrupted the view that the Earth was the center of the universe.

From New York Times