- Learn English
-
Learn grammar
-
List of words
-
Study your cards
-
Hang On, Man!
-
Audio Books
-
More apps
- Recent searches
-
au pair
-
scheme
-
adalia
-
actable
-
adam's needle
-
senior
-
forfeiture
-
actinide series
-
adagio
-
punctual
- Hide translation
actinium
actinium /ækˈtɪnɪəm/
noun
-
A radioactive element of the actinide series; found in uranium ores
(
Ac
, actinium
, atomic number 89
)
a radioactive element of the actinide series; found in uranium ores
