chemistry help?

Question

1.Thinking about the uses of radioactive isotopes,which statement is true?

A.The iodine isotope, i-27,is used to diagnose thyroid disorders

B.Radiation may be detected because it ionizes the atoms it affects

C.It's clearly understood that irridiation food kills bacteria and contaminates the food

D.Radiactive isotopes used in the medical diagnosis have long lives and are quickly absorbed by the body

Answer 1

A.) There is no isotope I-27. I-131 is used to treat some cancers of the thyroid, and I-123 is often used in nuclear imaging of the Thyroid.

B.) This depends on the type of radation.

C.) This is the true statement: irradation is used to sterilize food, specifically killing bacteria.

D.) This statement is half-true - the isotopes are quickly absorbed by the body, but they are used because they have *short* half-lives, otherwise they'd continue to be radioactive in the body.