Final answer:
The reason you can feel heat transfer in the form of infrared radiation from a nuclear bomb detonated 75 km away, but not x rays or γ rays, is because x rays and γ rays are absorbed by the atmosphere.
Step-by-step explanation:
The reason you can feel heat transfer in the form of infrared radiation from a large nuclear bomb detonated in the atmosphere 75 km from you, but none of the profusely emitted x rays or γ rays reach you is because x rays and γ rays are absorbed by the atmosphere. Infrared radiation, on the other hand, has longer wavelengths and can travel greater distances, allowing it to reach you despite the distance.