Final answer:
The electromagnetic radiation with a frequency of 3 x 10^17 Hz is most likely identified as gamma rays, which occupy the high-frequency end of the electromagnetic spectrum.
Step-by-step explanation:
Electromagnetic radiation detected with a frequency of 3 x 1017 Hz likely corresponds to a type of wave known as gamma rays. Electromagnetic waves are sorted into categories based on their frequencies, with gamma rays being at the high-frequency end of the spectrum. Given the provided frequency, we can reference the electromagnetic spectrum, which shows that gamma rays are higher in frequency than X-rays and ultraviolet radiation, indicating that the detected radiation is indeed in the gamma-ray range.