Additional Problems

| 47 | Mercury has an atomic mass of 201.970 617 u. Obtain the binding energy per nucleon (in MeV/nucleon).

| 48 | In electrically neutral atoms, how many (a) protons are in the uranium nucleus, (b) neutrons are in the mercury nucleus, and (c) electrons are in orbit about the niobium nucleus?

| 49 | ssm If the activity of a radioactive substance is initially 398 disintegrations/min and two days later it is 285 disintegrations/min, what is the activity four days later still, or six days after the start? Give your answer in disintegrations/min.

| 50 | Osmium (atomic mass = 190.960 920 u) is converted into Iridium (atomic mass = 190.960 584 u) via decay. What is the energy (in MeV) released in this process?

| 51 | Complete the following decay processes by stating what the symbol “X” represents (, , or ):

a. |
b. |
c. |
d. |

| 52 | Review Multiple-Concept Example 11 for help in approaching this problem. An archeological specimen containing 9.2 g of carbon has an activity of 1.6 Bq. How old (in years) is the specimen?

* | 53 | ssm www The photomultiplier tube in a commercial scintillation counter contains 15 of the special electrodes, or dynodes. Each dynode produces 3 electrons for every electron that strikes it. One photoelectron strikes the first dynode. What is the maximum number of electrons that strike the 15th dynode?

* | 54 | A sample of ore containing radioactive strontium has an activity of Bq. The atomic mass of strontium is 89.908 u, and its half-life is 29.1 yr. How many grams of strontium are in the sample?

* | 55 | Determine the symbol for the parent nucleus whose decay produces the same daughter as the decay of thallium .

** | 56 | Both gold ( days) and iodine ( days) are used in diagnostic medicine related to the liver. At the time laboratory supplies are monitored, the activity of the gold is observed to be five times greater than the activity of the iodine. How many days later will the two activities be equal?

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