radioactinium
The radioactive isotope of actinium, 22789Ac, having a half-life of 21.7 yearsThe radioactive isotope of actinium, 22789Ac, having a half-life of 21.7 years
Meaning
1 senses(uncountable)The radioactive isotope of actinium, 22789Ac, having a half-life of 21.7 years
Origin
From radio- + actinium.From radio- + actinium.
Wiktionary, CC BY-SA 4.0 · source
Synonyms
1 synonymsactinium-227
Lessons for this word
1 lessons- A1Countable and uncountable nouns — Because it can be uncountable