Exam 20: Nuclear Chemistry

It is believed that two carbon-12 nuclei can react in the core of a supergiant star to form sodium-23 and hydrogen-1. Calculate the energy released from this reaction for each mole of hydrogen formed. (1 kg = 6.022 × 10²⁶ amu; N_A = 6.022 × 10²³ mol^-1; C = 2.99792458 × 10⁸ m/s)

Gamma rays are high energy electrons.

Which of the following is injected into the bloodstream to trace the flow of blood and detect possible constrictions or obstructions in the circulatory system?

What is the nuclear process called in which a heavy nuclear of mass number greater than 200 divides to form smaller nuclei of intermediate mass and one or more neutron(s)?

Sodium-21 will emit positrons, each having an energy of 4.0 × 10^-13 J. What is this energy in MeV? (1 MeV = 1.602 × 10^-13 J)

For stable atoms of elements having low atomic numbers (≤ 20), the neutron-to-proton ratio is close to zero.

In passing through matter, alpha particles lose energy chiefly by causing

Cobalt-60 is a beta emitter with a half-life of 5.3 years. Approximately what fraction of cobalt-60 atoms will remain in a particular sample after 26.5 years?

Polonium-208 is an alpha emitter with a half-life of 2.90 years. How many milligrams of polonium from an original sample of 2.00 mg will remain after 8.00 years?

What is the name for spontaneous emission of particles or electromagnetic radiation by certain nuclei?

Which isotope, when bombarded with bismuth-209, would yield two neutrons and an isotope with atomic number 121 and mass number 299?

Iodine-131, t_1/2 = 8.0 days, is used in the diagnosis and treatment of thyroid gland diseases. If a laboratory sample of iodine-131 initially emits 9.95 × 10¹⁸ β particles per day, how long will it take for the activity to drop to 6.22 × 10¹⁷ β particles per day?

Electron capture is the capture of an electron-usually a 1s electron-by the ________.

Which is an incorrect representation of the indicated particle or nucleus?

What is the nuclear binding energy per nucleon for ? (1 kg = 6.022 × 10²⁶ amu; C = 2.99792458 × 10⁸ m/s) Particle Mass (amu) 24.985839 1.007276 1.008665

Present-day plant life has a carbon-14 decay rate of 16 disintegrations per minute (dpm) per gram of carbon. If a contemporary wooden chair were preserved for the next 3900 years, what ¹⁴C decay rate should be expected from the wood used to make the chair? (t_1/2 = 5730 yr)

The carbon-14 activity of some ancient Indian corn was found to be 7.0 disintegrations per minute (dpm) per gram of carbon. If present-day plant life has 16 dpm per gram of carbon, how old is the Indian corn? (t_1/2 = 5730 yr)

What is the name for the minimum mass of fissionable material required to generate a self-sustaining nuclear chain reaction?

In the following diagrams, A represents a radioactive isotope that decays into a new isotope, X. Each circle represents 1 mmol of atoms. t = 0: t = 25.0 s: Over the first 25.0 s, what is the disintegration rate of A?

Identify the missing species in the following nuclear transmutation.