Who discovered america and in what year was it

October 12, 1492 Christopher Columbus

Explanation:

Christopher Columbus officially set foot in the Americas, and claimed the land for Spain. It has been a national holiday in the United States since 1937. It is commonly said that "Columbus discovered America."

nuclear fission produces the atomic bomb, a weapon of mass destruction that uses power released by the splitting of atomic nuclei the fighting in iwo jima and okinawa affected the allies' pacific strategy because truman decided to drop the atomic bomb on mainland japan.