Question

Which one of the following isotopes of strontium is used as radioactive fallout?
1. Strontium-90
2. Strontium-85
3. Strontium-95
4. Strontium-80

Answer 1

Correct Answer - Option 1 : Strontium-90

• Strontium-90 (⁹⁰Sr) is a radioactive isotope of strontium produced by nuclear fission, with a half-life of 28.8 years.
• It undergoes β⁻ decay into yttrium-90, with decay energy of 0.546 MeV.
•  Strontium-90 has applications in medicine and industry and is an isotope of concern in the fallout from nuclear weapons and nuclear accidents.
• Naturally occurring strontium is nonradioactive and nontoxic at levels normally found in the environment, but ⁹⁰Sr is a radiation hazard.