An Isotope of Tc Having a Half-Life of 6

question 18

Multiple Choice

An isotope of Tc having a half-life of 6.0 h is used in bone scans. If a certain amount of this Tc is injected into the body, how long does it take for its initial decay rate to decrease BY 99%?

• A) 0.060 h
• B) 3.3 h
• C) 33 h
• D) 40 h
• E) slightly more than a month

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Definitions:

Amenorrhea

The absence of menstruation in a woman of reproductive age.

Premenstrual Dysphoric Disorder

A severe form of premenstrual syndrome characterized by significant mood swings, irritability, and depression.

Amenorrhea

The absence of menstruation in women of reproductive age for reasons other than pregnancy, breastfeeding, or menopause.