The largest KNOWN nuclear weapon was made by the Soviet Union (Russia) and was called the "Tsar Bomba" (King of Bombs). It had a yield of ~50MT.
The U.S.A.
The meaning of the word nuclear weapon, is a weapon that has a nuclear warhead on it.
The largest nuclear bomb ever detonated was the Soviet Union's Tsar Bomba in 1961, which had a yield of 50 megatons. It was the most powerful nuclear weapon ever created and tested.
theoretically the yield of nuclear weapons is unlimited.
* Earthquake Richter 5.0 = 32 kilotons nuclear weapon, like was used at Nagasaki * Earthquake Richter 6.0 = 1 megaton nuclear weapon * Earthquake Richter 7.0 = 32 megaton nuclear weapon * Earthquake Richter 7.1 = 50 megaton nuclear weapon, Tsar Bomba, the largest nuclear weapon ever tested * Earthquake Richter 8.0 = 1 gigaton nuclear weapon, much larger than anything ever made
The largest nuclear weapon ever tested, the Tsar Bomba by the Soviet Union in 1961, had a blast radius of over 7 miles. The fireball created by the explosion measured around 2 miles in diameter and the shockwave was felt over 400 miles away.
This nuclear weapon is called an atomic bomb or a nuclear bomb
Nuclear weapon detonations
If by "bomb" you mean a conventional explosive weapon, then the nuclear weapon is more powerful.
nuclear chemicals such as plutonium
No. LLNL even tested several Uranium-Hydride bombs in the 1950s. Even though their computer models said the devices should explode, none gave a nuclear yield. One could use the waste from the reactor as a Radiological Weapon, but the reactor itself is not useful as a weapon.
A nuclear explosion can be millions of times more powerful than the largest conventional weapon. For instance, the largest conventional bomb, the GBU-43/B MOAB, has a yield of about 11 tons of TNT, while the most powerful nuclear bomb ever tested, the Tsar Bomba, had a yield of approximately 50 megatons of TNT. This means a nuclear explosion can surpass conventional weapons in destructive capability by a factor of thousands to millions, depending on the specific devices being compared.