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.

---

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

---

Etymology

Origin of roentgenium

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