Question

Which of the following seems to be the use of an isotope of COBALT?

A) Used for treatment of goitre
B) Used in a nuclear reactor.
C) Used as a surface cleaner
D) Used for disinfecting tools used in a salon

Answer 1

Cobalt-60 is an isotope used in cancer therapy to emit focused gamma rays for treating tumors, requiring regular replacement due to its half-life.

Step-by-step explanation:

The isotope of cobalt commonly used in practical applications is Cobalt-60 (Co-60). This isotope emits gamma rays and is notably used in the medical field for the treatment of cancer. Cobalt-60 has the ability to focus radiation in small areas, particularly on targeted regions such as tumors.

This makes it highly effective in cancer therapy. Cobalt-60 machines are designed to swing through an arc, which concentrates the radiation on the cancerous tissue while minimizing exposure to the surrounding healthy areas. Given its radioactive nature, the intensity of cobalt-60's radiation is directly proportional to the amount of substance and its rate of decay, following first-order kinetics.

Therefore, a cobalt-60 source must be regularly replaced to maintain effectiveness due to its half-life of approximately 5.27 years.