What would happen if you launched a nuclear bomb into space

We've done it. It's called exoatmospheric testing. See: http://chemistry.about.com/od/photogalle…

Also: http://chasblogspot.blogspot.com/2009/03…

An Exoatmospheric Nuclear explosion would not burn because of the lack of oxygen.
It would however create an Electromagnetic Pulse which could knockout Satellites and maybe some Earth based Electronics.
Technically, if we were being attacked by Aliens from outside our atmosphere it could fry their Electrics and make them think twice about Earth, as it doesn't effect Biology.
It would create some lovely Auroras to boot!

That depends on the direction and velocity you launch it. If it's launched at a velocity below the escape velocity, then it falls back down. If it's launched with a velocity above the escape velocity, then it'll escape the Earth's gravity and continue on until it crashes into any other body (that could take billions of years).

It would be in space. If you detonated it then it would explode. Never mind that nuclear weapons HAVE been detonated in space, by the U.S. and the Soviets. The Soviets detonated 7 nuclear weapons at altitudes between 22km and 300km in 1961 and 1962. The U.S. detonated 14 nuclear weapons at altitudes between 26km and 540km between 1958 and 1962. Well, the U.S. launched 14, 4 of them failed to detonate.

Both the USA and USSR tested nuclear explosions in space in the 1960s. It is now prohibited by the 1967 Outer Space Treaty

The human race would hope the explosion wouldn't tear a hole in the ozone. The adverse temperatures could detonate it.

If you detonated it, it would explode.

There would be a nuclear bomb in space...

....Aliens ¬__________¬