Take a look at how atomic and hydrogen bobs actually work, and what the difference between the two is.
A lot of people think that atom bombs and hydrogen bombs are the same as they are both nuclear weapons. To a large extent, this is true as both bombs use nuclear energy to create their devastating explosions, but there is a difference between the two.
The main difference is in how they explode. Let's start off with breaking down the engineering of how the atomic bomb works. The atomic bomb has been around since the 1940s and is an incredibly simple weapon, well, at least to physicists. The atomic bomb needs to contain material that can be used to create a nuclear chain reaction from the fission of heavy nuclei. Usually, Uranium 235 is used. Uranium 235, as well as its isotopes, is radioactive, and that serves to play a vital role in the nuclear explosion. The explosion occurs due to a mass of fissile material concentrated in a particular place within the bomb, which is also known as critical mass. When critical mass is reached, it causes a chain reaction of nuclear decay which results in extreme energy release.
However, the nuclear bomb creates its devastation due to internal thermonuclear fusion (note that fission was used in the atomic bomb), which creates an extremely fast chain reaction thanks to materials such as deuterium and tritium as well as lithium hydride. However, these ingredients won't cause an explosion just by themselves, that is why the hydrogen bomb contains an integrated nuclear detonator device which, together with the ingredients, create a thermonuclear reaction with inside the bomb.
Frighteningly, there is no limit to the size to which you can make an atomic bomb. All you need is more ingredients and, thanks to the internal destination as well as the nuclear chain reaction taking place within microseconds, you could literally make a bomb that would wipe out all life on Earth.
Take a look at the video below by YouTube channel, Ridddle, on How Atomic and Hydrogen Bombs Work In 10 Minutes.