Technetium has not been found in nature. It can be obtained readily as a product of uranium fission in nuclear power plants, however, and is now produced in quantities of many kilograms per year. One medical use relies on the tendency of 99mTc (an excited nuclear state of 99Tc) to concentrate in abnormal heart tissue. Calculate the total activity (in disintegrations per second) caused by the decay of 1.0 mg of 99mTc, which has a half-life of 6.0 hours.

239 239Pu can be bombarded by a neutron and undergo nuclear fission to make an atom of 204 Au and an atom of 3lp. Write the balanced nuclear equation for the process. Make sure to show how many neutrons are given off by this reaction. Include the FULL isotope notation for ALL species involved.

Another series of nuclear reactions that can produce energy in the interior of stars is the cycle described below. This cycle is most efficient when the central temperature in a star is above 1.6 × 107 K. Because the temperature at the center of the Sun is only 1.5 × 107 K, the following cycle produces less than 10% of the Sun’s energy. (a) A high-energy proton is absorbed by 12 C. Another nucleus, A , is produced in the reaction, along with a gamma ray. Identify nucleus A decays through positron emission to form nucleus B. (c) Nucleus B absorbs a proton to produce nucleus C and a gamma ray. Identify nucleus C absorbs a proton to produce nucleus D and a gamma ray. Identify nucleus D. (e) Nucleus D decays through positron emission to produce nucleus E. Identify nucleus E. (f) Nucleus E absorbs a proton to produce nucleus F plus an alpha particle. What is nucleus F ? Note: If nucleus F is not 12C—that is, the nucleus you started with—you have made an error and should review the sequence…

Thorium  22890Th produces a daughter nucleus that is radioactive. The daughter, in turn, produces its own radioactive daughter, and so on. This process continues until bismuth 21883Bi is reached. What are (a) the total number Nα of α particles and (b) the total number Nβ of β- particles that are generated in this series of radioactive decays?

A wooden artifact is found in an ancient tomb. Its carbon-14 (146C)  activity is measured to be 63.0% of that in a fresh sample of wood from the same region. Assuming the same amount of 14C was initially present in the artifact as is now contained in the fresh sample, determine the age of the artifact.(in years)

A piece of charcoal used for cooking is found at the remains of an ancient campsite. A 1.19 kg sample of carbon from the wood has an activity of 2340 decays per minute. Find the age of the charcoal. Living mate- rial has an activity of 15 decays/minute per gram of carbon present and the half-life of 14C is 5730 y. Answer in units of y.

The decay chain of uranium includes radon, a noble gas. When uranium in the soil decays to radon, it may seep into houses; this can be a significant source of radiation exposure. Most of the exposure comes from the decay products of radon, but some comes from alpha decay of the radon itself. If radon in the air in your home is at the maximum permissible level, the gas in your lungs will have an activity of about 0.22 Bq. Each decay generates an alpha particle with 5.5 MeV of energy, and essentially all that energy is deposited in lung tissue. Part A Over the course of 1 year, what will be the dose equivalent in Sv to the approximately 0.90 kg mass of your lungs? Express your answer in millisieverts per year. ΕΧΕΙ ΑΣΦ dose equivalent = ? mSv/yr