Israel, as they refuse to acknowledge they have the weapons; and North Korea.
USA, Russia, UK, PRC, France, India, Pakistan, North Korea are known for having nuclear weapon. Israel probably also owns nuclear weapon but never officialy declared it.
The meaning of the word nuclear weapon, is a weapon that has a nuclear warhead on it.
United States and Israel, and possibly other nations.
Israel Weapon Industries was created in 2005.
This nuclear weapon is called an atomic bomb or a nuclear bomb
Nuclear weapon detonations
USA, Russia, UK, France, China, India, Pakistan, Israel. Query on North Korea - ask CIA.
If by "bomb" you mean a conventional explosive weapon, then the nuclear weapon is more powerful.
nuclear chemicals such as plutonium
NO
no