7.2 Nuclear Reactions

Which of the following best describes the concept of binding energy in an atomic nucleus?

A. The energy required to break the nucleus into its constituent protons and neutrons.

B. The energy released when a nucleus undergoes fission.

C. The energy required to add an extra neutron to the nucleus.

D. The energy released during the fusion of two light nuclei.

In a nuclear reactor, what purpose does the moderator serve?

A. To absorb excess neutrons.

B. To speed up the neutrons.

C. To slow down the neutrons.

D. To initiate the fission process.

Which of the following conditions is NOT required for nuclear fusion to occur?

A. High temperature.

B. High pressure.

C. Presence of a magnetic field.

D. Presence of heavy nuclei.

The Large Hadron Collider (LHC) is an example of which type of particle accelerator?

A. Cyclotron.

B. Synchrotron.

C. Linear accelerator.

D. Betatron.

What is the primary reason for pursuing controlled nuclear fusion on Earth?

A. To produce radioactive isotopes.

B. To generate electricity without producing greenhouse gases.

C. To study the behaviour of plasma.

D. To produce heavy elements.

a) Define the concept of binding energy and explain its significance in nuclear reactions. [3]

b) Given that the mass of a proton is 1.0073 u and the mass of a neutron is 1.0087 u, calculate the binding energy of the helium-4 nucleus, which has a mass of 4.0015 u. Use the energy-mass equivalence principle, E=mc^2, where c is the speed of light (3 x 10^8 m/s). [4]

a) Describe the process of nuclear fission and its significance in energy production. [3]

b) A particular fission reaction releases an energy of 200 MeV. If a nuclear reactor carries out 10^20 such reactions per second, calculate the power output of the reactor. [4]

a) Explain the conditions required for nuclear fusion to occur and its significance in stars. [3]

b) The fusion of two deuterium nuclei produces a helium nucleus, a neutron, and an energy of 3.27 MeV. If the Sun undergoes 10^38 such fusion reactions every second, calculate the energy released by the Sun in one day. [4]

a) Explain the concept of half-life in radioactive decay and its practical applications. [3]

b) A radioactive substance has a half-life of 10 hours. If you start with 1 gram of this substance, calculate how much of it remains after 30 hours. [4]

c) Discuss the advantages and limitations of using radioactive dating techniques to estimate the age of geological samples. [3]

a) Describe the basic functioning of a cyclotron in accelerating charged particles. [3]

b) A cyclotron accelerates protons to a kinetic energy of 50 MeV. Calculate the speed of these protons, and explain any relativistic effects that may be observed at this speed. [4]

c) Discuss the significance of cyclotrons in particle physics research and medical applications. [3]