Abbreviation for "Hydrogen Bomb". The hydrogen bomb is the big
brother of the first nuclear bombs, Fat Man and Little
Boy, which were dropped on Nagasaki and Heroshima in 1945.
The hydrogen bomb uses a hydrogen neutron, fired at high
speed, into an atom of some unstable element, usually uranium. This causes the uranium particle to separate. This, in turn, releases alot of enegry. The two halfs then proceed to
re-do the above steps in a Chain Reaction, which is called fission.
----------------------------------
EDIT: Actually it fuses together the neutrons of hydrogen in a thermonuclear reaction, not split apart the uranium.
Usually with a blast diameter of 10+
miles, as opposed to
1 mile diameter for an A bomb.