atomic number 89

Thesaurus

Noun

1.atomic number 89 - a radioactive element of the actinide series; found in uranium oresAc, actiniumchemical element, element - any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matteruranium ore - any ore from which uranium can be extracted