Nuclear fusion and thermonuclear reactions
Nuclear energy · Physics
Bohr atom
Interactive 3DElectrons orbit the nucleus in shells — switch element to see H, He and Li fill their shells.
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Study notes
(a) D–T fusion releases 17.6 MeV per reaction. How much energy does 1 kg of D–T fuel (50/50 by mass) release? (b) Compare with 1 kg of ²³⁵U fissioned (~200 MeV per nucleus). Solution: (a) Average mass per reaction ≈ 2.5 u = 4.15×10⁻²⁷ kg. Reactions per kg = 1/4.15×10⁻²⁷ ≈ 2.4×10²⁶. Energy = 2.4×10²⁶ × 17.6 × 1.602×10⁻¹³ ≈ 6.8×10¹⁴ J/kg. (b) ²³⁵U: reactions per kg = 1/(235×1.66×10⁻²⁷) ≈ 2.56×10²⁴; × 200 MeV = 2.56×10²⁴ × 3.2×10⁻¹¹ ≈ 8.2×10¹³ J/kg. Fusion gives ~8× more energy per kg of fuel!