Which isotopes fuse in a hydrogen bomb to release energy?

• A. Uranium-235 and Plutonium-239
• B. Helium-3 and Helium-4
• C. Neon-20 and Sodium-23
• D. Deuterium and Tritium

Answer: (D)

In a hydrogen bomb, the energy comes from fusing light hydrogen isotopes. The fusion fuel is deuterium and tritium, which when they collide fuse to form helium-4 and a fast neutron, releasing a large amount of energy. This reaction, known as deuterium-tritium fusion, has a high probability at the extreme temperatures and pressures produced in a thermonuclear device, which is why it’s the standard fusion pair used in these weapons. The device’s fission stage provides the necessary heat and pressure to ignite this fusion.

The other options involve materials that are not the typical fusion fuel for this context. Uranium-235 and Plutonium-239 are used for fission reactions, not fusion. Helium-3 and Helium-4 are both helium nuclei and aren’t the practical fusion partners in this type of weapon. Neon-20 and Sodium-23 are not hydrogen isotopes and don’t undergo the same fusion processes.