They didn't decide they were going to bomb Hiroshima - they decided they were going to use the atomic bomb on Japan. The US gave Japan two separate warnings that they would employ (paraphrase) a "terrible new weapon", if unconditional surrender was not forthcoming. Japan refused, and that was the first atomic bomb drop. Hiroshima was not finalized as a target until the B-29 was in the air for several hours (weather considerations). Genuinely shocked by Hiroshima, Japan nonetheless dug in it's heels, betting the first atomic bomb was a one-shot deal. Nagasaki brought Japan to it's knees.
Japan refused to surrender after the bombing of Hiroshima.
The US
No
Truman
Hiroshima
They used airplanes.'
The atomic bomb was dropped on Hiroshima Nagasaki by the US from parachute.
Hiroshima
Hiroshima
US Air Force
If you mean the US, yes.
Over Hiroshima and Nagasaki.