What phenomenon results in the loss of energy of a radio wave and affects communication over long distances?

The phenomenon that leads to the loss of energy of a radio wave and significantly impacts communication over long distances is multipath propagation. This occurs when a transmitted radio signal bounces off various surfaces—like buildings, hills, or the ground—before it reaches the receiver.

As the signal reflects off these surfaces, it can take multiple paths to arrive at the destination, which can lead to constructive or destructive interference. When signals are in phase, they can reinforce each other, but when they are out of phase, they can cancel each other out. This can result in signal fading and fluctuations in signal strength, making it difficult for the receiver to maintain a clear and consistent communication link over long distances.

This makes multipath propagation especially problematic in urban environments where obstacles are plentiful, affecting the reliability of the received signal. Other factors like interference, reflection, and diffraction also affect radio wave propagation, but they do not mix as significantly with the loss of energy due to the various paths produced in multipath scenarios.