Fission vs Fusion ✏ Chemistry In a Nutshell

Rucete ✏ Chemistry In a Nutshell

1. Nuclear Fission

• Definition: A large atomic nucleus splits into two or more smaller nuclei.
• Key Characteristics:
  • Causes element transformation (new elements form).
  • Produces free neutrons, photons, alpha (α) and beta (β) particles.
  • Occurs in heavy elements (e.g., uranium, plutonium).
  • Exothermic reaction (releases a large amount of energy).
  • Emits gamma rays and kinetic energy from nuclear fragments.
• Example Reaction (U-235 Fission):   
• $${92}_{235}^{}U+1^{0}n\to {}_{56}^{141}Ba+{}_{36}^{92}Kr+3(1^{0}n)+\text{energy}$$
• U-235 + 1 neutron → Ba-141 + Kr-92 + 3 neutrons + energy
  (Uranium absorbs a neutron and splits, releasing energy and more neutrons for a chain reaction.)

2. Nuclear Fusion

• Definition: Two smaller atomic nuclei combine to form a larger, heavier nucleus.
• Key Characteristics:
  • Occurs in stars (e.g., the Sun).
  • Releases much more energy than fission.
  • Requires extremely high temperatures and pressure.
  • No radioactive waste (compared to fission).
  • Primary reaction in hydrogen bombs.
• Example Reaction (Hydrogen Fusion):$${}_1^{1}H+{}_1^{1}H\to {}_1^{2}H+e^{+}$$
  (Hydrogen nuclei fuse to form deuterium and a positron, continuing to form helium.)

In a nutshell

Feature	Fission	Fusion
Process	Splitting of a heavy nucleus	Combining of light nuclei
Energy Released	Large	Much larger than fission
Common Fuel	Uranium-235, Plutonium-239	Hydrogen isotopes (Deuterium, Tritium)
Conditions Required	Room temperature with neutron bombardment	Extremely high temperature and pressure
Examples	Nuclear power plants, atomic bombs	The Sun, hydrogen bombs
Waste Production	Produces radioactive waste	Little to no radioactive waste