A hydrogen bomb is considered a radioactive bomb. They tested hydrogen bombs in New Mexico and they are just as powerful if not more powerful than a nuclear bomb. They also produce a lot of radiation. So, hydrogen has a lot to do with radiation.
@Ben-Siraphob(View Post) Hydrogen has a lower velocity and can remain on the screen indefinitely, since it is slower and lasts longer than the radiation, it theoretically is more effective at transferring heat, so it's pretty much an upgrade.
@randalserrano hydrogen bombs are much much much more powerful than normal nuclear devices. This is because the main explosion from a H-bomb is from the fission of the hydrogen into helium which releases a huge amount of energy. I wish they would implement hydrogen fusion into Powder Toy. To show the strength, The Tzar Bomba, the stongest bombe ever build (a H-Bomb) created a explosion equal to 50 Megatons of TNT, while the Fat Man, the nuclear bomb dropped on Nagasaki, made a explosion of about 21 Kilo tonnes of TNT which is much much less