5.4 Nuclear Fission and Fusion

5.4 Nuclear Fission and Fusion

Explanation:

Nuclear fission is the process by which a heavy atomic nucleus splits into two lighter nuclei, accompanied by the release of energy. In contrast, nuclear fusion is the process where two light atomic nuclei combine to form a heavier nucleus, also releasing energy. Both processes are sources of enormous energy, with fusion being the reaction that powers the sun.

Key Concepts:

• Nuclear Fission: The splitting of a heavy nucleus (e.g., Uranium-235) into lighter nuclei.
• Nuclear Fusion: The merging of light nuclei (e.g., Hydrogen isotopes) to form a heavier nucleus.

Example Problem:

Problem: If each fission of a Uranium-235 nucleus releases about 200 MeV of energy, calculate the total energy released by the fission of 1 kg of Uranium-235.

Solution:

• Number of Uranium-235 atoms in 1 kg:

Number of Uranium-235 atoms in 1 kg = 1000 g / 235 g/mol × 6.022 × 10^{23} atoms/mol

• Total energy released = Number of atoms × Energy per fission.

Total energy = 2.56 × 10^{13} MeV