Fusion

Definition

Fusion is a nuclear reaction where two light atomic nuclei combine to form a heavier nucleus, releasing a significant amount of energy. This process powers stars, including the sun.

5 Must Know Facts For Your Next Test

1. Fusion requires extremely high temperatures and pressures to overcome the electrostatic repulsion between positively charged nuclei.
2. The most common fusion reaction in stars combines hydrogen isotopes to form helium.
3. Fusion reactions release more energy per unit mass than fission reactions, making them a potent source of energy.
4. Controlled fusion for energy production on Earth remains experimental due to the challenges of achieving and maintaining the necessary conditions.
5. $E = mc^2$ explains the mass-energy equivalence principle that underpins why fusion releases so much energy.

Review Questions

• What conditions are necessary for nuclear fusion to occur?
• Why does fusion release more energy compared to fission?
• Explain how $E = mc^2$ relates to nuclear fusion.

Related terms

Fission:

A nuclear reaction where a heavy nucleus splits into smaller nuclei with the release of energy.

$E = mc^2$: Einstein's equation representing the relationship between mass and energy, crucial for understanding nuclear reactions.

Plasma: A state of matter consisting of ionized gas, essential for achieving the high-temperature conditions needed for fusion.