Exam 42: Nuclear Physics

An excited U* nucleus undergoes fission into two fragments, as shown: U* → Ba + Kr The following atomic masses are known: Kr: 91.926270 u Ba: 143.922845 u U*: 236.045563 u What is the reaction energy, in MeV, for this process? (1 u = 1.6605 × 10^-27 kg = 931.5 MeV/c²)

A radioactive atom has 98 protons and 249 nucleons. If it undergoes alpha decay, what are the number of protons and nucleons, respectively, in the daughter nucleus?

A certain isotope has a half-life of 32.4 hr and a relative biological effectiveness of 3.50. A sample of this isotope initially delivers an absorbed dose of 0.240 Gy to 250 g of tissue. (a) What was the initial equivalent dose to the tissue in rem and in sieverts? (b) How many joules of energy did the 250-g sample initially receive from the isotope?

The stability of Fe with respect to alpha, β+, and β- decay is to be determined. Do not consider the possibility of decay by electron capture. The following atomic masses are known: He: 4.002603 u Cr: 51.944768 u Mn: 55.938907 u Fe: 55.934939 u Co: 55.939841 u The Fe nuclide is

For a atom, the number of protons, neutrons, and electrons in the atom is

If a nucleus decays by alpha decay to a daughter nucleus, which of the following statements about this decay are correct? (There may be more than one correct choice.)

Two identical nuclei of mass 18 u are made to unite to make a single nucleus of mass 36 u. What is the radius of the result of this fusion?

A certain substance has a half-life of 5.0 hours. How many nuclei of the substance are required to give an initial activity of 6.0 μCi? 1 Ci = 3.7 × 10¹⁰ Bq.

If a nucleus had a diameter of 8.0 fm, what would be its expected mass, in atomic mass units?

The set of nuclear reactions that power our sun can be summarized a 4p+ → ⁴He+2 + 2e+. The masses of the particles involved are 938.272 MeV/c² (proton, p⁺), 3727.38 MeV/c² (alpha particle, ⁴He⁺²), and 0.511 MeV/c² (positron, e+). How much energy is released by each set of these reactions?

The reaction ²H + ²H →? ³H + ¹H releases 4.03 MeV of energy. If 1.0 kg of deuterium were to go through this reaction, how much energy would be produced? (1 eV = 1.60 × 10^-19 J, mdeuterium = 2.012 u, 1 u = 931.5 MeV/c² = 1.6605 × 10^-27 kg)

What is the binding energy per nucleon for Al? The neutral Al atom has a mass of 26.981539 u; a neutral hydrogen atom has a mass of 1.007825 u; a neutron has a mass of 1.008665 u; and a proton has a mass of 1.007277 u. (1 u = 931.494 MeV/c²)

Which of the following statements about the atomic nucleus is correct? (There may be more than one correct choice.)

In a laboratory accident a work area is contaminated with radioactive material. Health physicists monitor the area during a 30-day period and, after correcting for the background rate, obtain the data shown in the table. The accident occurred at t = 0. They determine that it will not be safe for workers to enter the area until the radioactivity level has dropped to 133 counts per minute. Of the choices listed below, which one is the earliest time that workers could safely return?

A certain nucleus containing 8 protons and 7 neutrons has a radius R. Which of the following values would be closest to the expected value of the radius of a nucleus having 51 protons and 69 neutrons?

An archaeologist finds the ¹⁴C in a sample of 3.10 g of material to be decaying at 107 counts per second. A modern 1.00-g sample of the same material decays at 151 counts per second. The half-life of ¹⁴C is 5730 y. How old is the sample?

The stability of Sc with respect to alpha, β+, and β- decay is to be determined. Do not consider the possibility of decay by electron capture. The following atomic masses are known: He: 4.002603 u K: 42.960717 u Ca: 46.954543 u Sc 46.952409 u Ti: 46.951764 u The Sc nuclide is

In the nuclear reaction B + He → H + X, which of the following is the missing nuclear product X?

The following masses are known: n (neutron) 1.008665 u H 1.007825 u Fe 56.935399 u What is the binding energy of Fe, in MeV? (1 u = 1.6605 × 10^-27 kg = 931.5 MeV/c²)

For the missing product X in the nuclear reaction neutron + O → X + alpha particle determine the atomic mass and atomic number of X, and write X in the standard form. It is NOT necessary to identify which atom X is.