22.3 Nuclear Reactions

Any process that involves a change in the nucleus of an atom is called

• nuclear fusion.

• nuclear binding.

• nuclear fission.

• a nuclear reaction.

Which of the following processes correctly describes a nuclear fission reaction?

• Two light nuclei bind together to produce a heavier nucleus and energy.

• Two heavy nuclei bind together to produce heavier nuclei and energy.

• A heavy nucleus splits to produce lighter nuclei and energy.

• A heavy nucleus absorbs energy to produce lighter nuclei.

What value must the mass number of an isotope be greater than for fission to occur?

• 26

• 58

• 83

• 112

What type of particle is captured by other nuclei in a nuclear chain reaction, triggering additional fission events?

• electrons

• protons

• neutrons

• neutrinos

The energy released in a fission event is _________ relative to the energy released in typical chemical reactions.

• moderately

• very large

• fairly small

• about equal

When neutrons released in a fission event are captured by other nuclei, making these nuclei unstable, this triggers additional fission events, which lead to the possibility of a

• melt down.

• nuclear explosion.

• radioactive release.

• chain reaction.

What is a nuclear reactor?

• a system designed to increase the energy released from a chain reaction

• a system designed to start a fission chain reaction within heavy elements

• a system designed to start an uncontrolled, self-sustained chain reaction

• a system designed to start and maintain a controlled, self-sustained chain reaction

All stars generate energy through

• fusion

• fission and fusion

• fission

• chemical reactions between hydrogen atoms

Because fusion reactions produce heavier nuclei, the binding energy per nucleon must increase as atomic number increases. This is possible only for atoms in which A < 58. Consequently, fusion occurs naturally only for

• heavy atoms.

• light atoms.

• either heavy or light atoms.

• medium atoms.

Which of the following is not an advantage of nuclear fusion reactors?

• Deuterium, the fuel used for fusion, is easily obtained from water.

• Fusion reactions produce few radioactive byproducts.

• The high temperatures required are difficult and expensive to obtain and maintain in a laboratory or power plant.

• The fuel costs of a fusion reactor would be relatively low.