What is Nuclear weapon?
A '''nuclear weapon''', '''nuclear bomb''' or a '''nuke''', is a [[weapon]] that suddenly releases the [[energy]] in the nucleus of certain types of [[atom]]s. When triggered, the device releases a huge amount of energy in the form of a [[nuclear explosion]]. Nuclear explosions can destroy a city and kill most of its people. They also make [[nuclear fallout]]. This [[radioactive]] material can make people ill. Nuclear weapons are the most damaging weapons mankind has created. The first nuclear weapons were built by the [[United States]] during [[World War II]]. Two nuclear weapons were used to [[atomic bombings of Hiroshima and Nagasaki|attack cities in Japan]]. They were the only times nuclear weapons were used in [[war]]. There are two types of nuclear weapons: fission weapons (also called atomic bombs or A-Bombs) and [[fusion weapons]] (also called hydrogen bombs, H-Bombs, or thermonuclear weapons). They make energy for the nuclear explosion in different ways. Fusion weapons make bigger explosions. Fission weapons use a special [[isotope]] of [[uranium]] or [[plutonium]]. Fusion weapons use a special isotope of [[hydrogen]]. Nuclear weapons have been used twice in war, both by the United States in the atomic bombings of [[Hiroshima]] and [[Nagasaki]] in 1945. Since the atomic bombings of Hiroshima and Nagasaki, nuclear weapons have been detonated over 2,000 times for testing and demonstration. Only a few nations possess such weapons or are suspected of seeking them. The only countries known to have detonated nuclear weapons and to say they have them are (in order from the first time the country had tested them) the United States, the Soviet Union (succeeded as a nuclear power by Russia), the United Kingdom, France, China, India, Pakistan, and North Korea. Israel is believed to have nuclear weapons, but in a policy of deliberate ambiguity, does not say so. Germany, Italy, Turkey, Belgium and the Netherlands share nuclear weapons with other countries. South Africa is the only country that has in