The half life of mercury 197 is 64.1 hrs.

1.If a patient undergoing a kidney scan is given 5.0 of mercury-197, how much will remain after 9 days?

2. 26 days?

Gold-198, a emitter used to treat leukemia, has a half-life of 2.695 days. The standard dosage is about 1.0 body weight.

3.How long does it take a 30.0 sample of gold-198 to decay so that only 7.50 remains?

4.How many millicuries are required in a single dosage administered to a 61 adult?

5. Balance the equation

10/5B + 1/0n --> ? + 4/2He

6. Phosphorus-32 has a half-life of 14.0 . Starting with 8.00 of , how many grams will remain after 42.0 ?

7.Carbon-14 has a half-life of 5730 . In a plant fossil, you find that the has decayed to 1/16.0 of the original amount. How long ago was this plant alive?