How do fission bombs differ from thermonuclear bombs in explosive yield?

Fission bombs (atomic bombs) and thermonuclear bombs (hydrogen bombs) differ significantly in their explosive potential. While fission bombs rely on the splitting of heavy atomic nuclei, thermonuclear bombs utilize a multi-stage process involving both fission and nuclear fusion, allowing for vastly greater power.21

The explosive yield of fission bombs is typically measured in kilotons, with each unit representing the force of 1,000 tons of TNT. In contrast, the power of thermonuclear bombs is often expressed in megatons, where one unit equals the force of 1,000,000 tons of TNT. Consequently, thermonuclear weapons can be hundreds or even thousands of times more powerful than fission devices.2

There is no theoretical limit to the size or yield of a thermonuclear weapon, as additional stages can be added to the design; however, practical constraints regarding the size and weight of deliverable weapons impose limits on their actual construction. While fission weapons are limited by the physics of the chain reaction, thermonuclear designs leverage the fusion of light nuclei to achieve their immense destructive capacity.32