To save this word, you'll need to log in.
Definition of strontium 90
: a heavy radioactive isotope of strontium of mass number 90 that has a half-life of 29 years, that is present in nuclear waste and fallout, and that is hazardous because like calcium it can be assimilated in biological processes and deposited in the bones of human beings and animals
Keep scrolling for more
Keep scrolling for more
Comments on strontium 90
What made you want to look up strontium 90? Please tell us where you read or heard it (including the quote, if possible).
Test Your Vocabulary
More Confusing Words—Quiz
- The magician
______moved the selected card to the top of the deck.
Can you spell these 10 commonly misspelled words?
TAKE THE QUIZ
Test Your Knowledge - and learn some interesting things along the way.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridgedWords at Play
Ask the Editors
Word Games
- More Confusing Words—Quiz
How many of these commonly confused words do you know?
Take the quiz - Name that Thing: Toys and Games Edition
It's all fun and games until someone beats your high score.
Take the quiz - Spell It
Can you spell these 10 commonly misspelled words?
Take the quiz - Add Diction
Build a chain of words by adding one letter at a time.
Play the game
Share strontium 90
Time Traveler for strontium 90
The first known use of strontium 90 was in 1952
See more words from the same year