My American History professor told my class in her lecture that the Japanese were given the opportunity to surrender after Hiroshima being nuked and wanted to but were unable to because it knocked out their communication systems. Were their communications really rendered ineffective and did they really attempt to surrender? I’ve not heard this anywhere else.
This has gotten a little confused on several points somewhere along the way. The atomic bomb cut off communications with the city of Hiroshima, which made it difficult for the Japanese to verify what had happened there. That's the only relevant communications cut-off. The Japanese did take several days to confirm what had happened, and the US did not build that into their bombing strategy at all (the timing of the bombings was ultimately determined by the weather conditions, not anything diplomatic), so the bombing of Nagasaki occurred prior to the Japanese being able to discuss what had happened at Hiroshima in any detail. But the Japanese did not agree to unconditional surrender immediately after Nagasaki, either — and it isn't clear exactly what influenced their decision to offer a conditional surrender on August 10 (e.g., the role of the Soviet invasion).
See this previous answer of mine that goes over the timeline of events fairly closely.