1: German scientists told the United States that the United States developed it first. The moustache still has no curly hair.
2: In terms of mass-to-energy conversion rate, nuclear fusion is about 4 times stronger than nuclear fission. However, the power of nuclear weapons is measured in units of yield (just like an ordinary bomb, the more gunpowder you put into it, the more powerful it is, and the same is true for nuclear weapons). There are several thousand tons, and there are also 50 million tons.
3: Yes
4: Currently, nuclear warheads are basically delivered by missiles. In the past, they were also directly air-dropped. During the Cold War, there were even artillery-launched nuclear bombs, nuclear landmines, Nuclear torpedo.
5: Yes
6: In terms of pure physical lethality, the hydrogen bomb is still the largest. But in terms of damage to people, genetic weapons are even more terrifying than hydrogen bombs.
7: United States
8: Pure nuclear fusion is not radioactive. The reason why hydrogen bombs have radiation is because they are detonated by atomic bombs, so they will also produce certain Radiation, but less than an atomic bomb.