When do radio waves typically experience the greatest loss of energy?

Radio waves typically experience the greatest loss of energy when they are absorbed. Absorption occurs when the energy from radio waves is transferred to the material they encounter, such as the atmosphere, buildings, or other surfaces. This energy transfer results in the conversion of the wave's energy into other forms, such as heat, leading to a significant reduction in signal strength and quality.

In contrast, while radio waves can lose some energy when reflected, refracted, or transmitted, those processes do not usually cause as much energy loss as absorption. Reflection involves bouncing off surfaces, which may cause scattering but retains most of the wave's energy. Refraction bends the waves as they pass through different media, changing their direction but not significantly impacting their energy. Transmission allows waves to pass through materials, potentially weakening them but not to the extent seen in absorption. Thus, absorption is the most impactful in reducing the energy of radio waves.