- Learn English
-
Learn grammar
-
List of words
-
Study your cards
-
Hang On, Man!
-
Audio Books
-
More apps
- Recent searches
-
adding machine
-
addible
-
adelie coast
-
addressable
-
adelgid
-
hardy
-
adder's fern
-
addressograph
-
addicted
-
add up
- 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
