Which type of radiation do all objects emit and absorb?

All objects emit and absorb infrared radiation due to their temperature. This phenomenon is explained by the laws of thermodynamics, particularly that any object at a temperature above absolute zero emits electromagnetic radiation. The amount and wavelength of this radiation depend on the object's temperature.

As objects get warmer, they emit more infrared radiation, which is part of the electromagnetic spectrum. This is why, for example, warm bodies like humans or heated objects can be detected by infrared cameras. At the same time, objects can also absorb infrared radiation from their surroundings, maintaining thermal equilibrium.

While objects can emit other types of radiation like visible light or ultraviolet radiation, this emission is typically dependent on certain conditions or temperature thresholds. Infrared radiation, however, is universally emitted and absorbed by all objects, making it the correct answer in this context.