probably the hydrogen bomb 100x bigger blast than atomic
Largest in size or yield? Or current largest?
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.
USSR
Nobody, the US was the first country to work out how to actually make nuclear weapons.
The atoll used by the US for nuclear weapons testing is called Bikini Atoll, located in the Marshall Islands in the Pacific Ocean. The infamous Castle Bravo test, the largest nuclear weapon ever detonated by the US, took place there in 1954.
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.
The US performed the first nuclear weapon test on July 16, 1945.
End of WW2.
The major revenue of US comes from their weapon business. They are the largest weapon seller in the world.
It was discovered that Canada had one of the world's largest mineable deposits of high grade Uranium ore. During the fastest part of the US nuclear weapon/energy expansion the US bought most of its Uranium from Canada.