Answer:
2.73 K
Step-by-step explanation:
The Cosmic Microwave Background (CMB) radiation are a type of electromagnetic radiations that are released after the explosion of the big bang. It propagates in all direction in space and is moving further with the expansion of the universe. They are not visible but they are helpful in estimating the age of the universe.
These radiations have a wavelength of about 970 μm (approximately 1 mm).
The temperature of the corresponding blackbody of this radiation is approximately 2.73 K(-270.42°C) and its extremely cold.