[ uhn-uh-nil-ee-uh m ]
/ ˌʌn əˈnɪl i əm /

noun Chemistry, Physics.

former name of darmstadtium. Symbol: Uun
Also called element 110.

Definition for ununnilium (2 of 3)


[ dahrm-stat-ee-uh m ]
/ dɑrmˈstæt i əm /

noun Chemistry, Physics.

a superheavy, synthetic, radioactive element with a very short half-life. Symbol: Ds; atomic number: 110.

Origin of darmstadtium

named after Darmstadt, the city in Germany where it was first created; see -ium
Formerly ununnilium, element 110.

Definition for ununnilium (3 of 3)

element 110

noun Chemistry, Physics.

Formerly ununnilium.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Science definitions for ununnilium


[ därm′shtätē-əm ]


A synthetic radioactive element, first produced by bombarding lead atoms with nickel atoms. It has a mass number of 281, and its most stable isotope has a half-life of over one minute. Atomic number 110. See Periodic Table.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.