Nuclear Fission & Fusion

Introduction to Nuclear Reactions

Nuclear reactions involve changes in an atom's nucleus and can release a large amount of energy. The two main types of nuclear reactions are fission and fusion.

Nuclear Fission

• Definition: Fission is the process of splitting a heavy nucleus into two lighter nuclei, along with a few neutrons and a large amount of energy.
• Example: Uranium-235 is a common fuel used in nuclear reactors. When it absorbs a neutron, it becomes unstable and splits into smaller nuclei like Barium and Krypton, releasing energy.
• Applications: Used in nuclear power plants to generate electricity and in atomic bombs.

Nuclear Fusion

• Definition: Fusion is the process where two light atomic nuclei combine to form a heavier nucleus, releasing energy in the process.
• Example: In the sun, hydrogen nuclei fuse to form helium, which releases a tremendous amount of energy.
• Applications: Potentially used for future clean energy sources; currently used in hydrogen bombs.

Binding Energy and Mass Defect

• Binding Energy: The energy required to break a nucleus into its individual protons and neutrons. It is a measure of the nucleus's stability.
• Mass Defect: The difference between the mass of a nucleus and the sum of the masses of its individual nucleons. This "missing mass" is converted into binding energy according to Einstein's equation: $$E = mc^2$$

Nuclear Reactors

Nuclear reactors use controlled fission reactions to generate electricity. They contain fuel rods, control rods, and a moderator to manage the reaction rate and ensure safety.

Radiation

Radiation is the emission of energy as electromagnetic waves or as moving subatomic particles. It can be harmful to living organisms, so safety measures are crucial in nuclear technology.