What are nuclear weapons?

Nuclear weapons are enormously powerful explosives which get their energy from splitting or joining tiny particles inside an atom.

They can be more powerful than even the biggest non-nuclear bombs and the explosions they produce are so powerful that just one nuclear bomb can destroy a large city.

They were used twice against Japan during World War 2, and that's the only time they have been detonated in war.

Click here to read about what happened at Hiroshima and Nagasaki