A neutron bomb is a particularly horrific kind of bomb. It is less powerful than a hydrogen bomb, but very, very deadly to living things. To operate, it uses the same nuclear reaction as a conventional hydrogen bomb: the fusing of atoms of deuterium and tritium, both of which are "isotopes" of hydrogen -- in other words, they act like hydrogen atoms but are much heavier because they contain particles called neutrons also.

These bombs work by using large amounts of pressure and heat generated in another nuclear reaction called fission (used in the much smaller atomic bomb) to smash the atoms of deuterium and tritium together to form larger atoms similar to hydrogen. The nuclear reaction releases a tiny amount of energy, as well as a free neutron. This tiny amount of energy, when multiplied by the number of atoms undergoing the reaction, turns out to be a huge amount of total energy, resulting in a large explosion. In a conventional warhead, many of the released neutrons get used up by generating a third fission explosion. So, really, you could say that there are three nuclear bombs in a single hydrogen bomb, which is pretty scary.

In a neutron bomb, however, the neutrons are allowed to escape instead of igniting the third bomb. It results in a smaller explosion but a very large number of neutrons. Well, neutrons are just another form of radiation. The high speed neutrons tend to leave buildings and machines unharmed but kills any animal (or person) within a certain distance of the blast.