Actinium
[æk'tɪnɪəm]
Definition
(noun.) a radioactive element of the actinide series; found in uranium ores.
Editor: Wilma--From WordNet
Definition
(n.) A supposed metal, said by Phipson to be contained in commercial zinc; -- so called because certain of its compounds are darkened by exposure to light.
Checked by Llewellyn
Examples
- In 1899 Debierne discovered, also in the highly complex pit chblende, actinium, which has proved considerably less radioactive than radium. Walter Libby. An Introduction to the History of Science.
Checked by Carmen