TeXes Science Practice Test

What happens to approximately 50% of the solar energy directed toward Earth?

1. It is absorbed or reflected by the atmosphere

2. It reaches the Earth's core

3. It immediately radiates back into space

4. It is solely used by plants for photosynthesis

The correct answer is: It is absorbed or reflected by the atmosphere

The correct response highlights that approximately 50% of the solar energy directed toward Earth is either absorbed or reflected by the atmosphere. This interaction is crucial for understanding the Earth's energy balance. When solar radiation reaches our atmosphere, some of it is absorbed by gases, clouds, and aerosols, while the rest is reflected back into space. This process helps regulate the temperature of the Earth and influences weather patterns. In contrast, the other options do not accurately represent what occurs with solar energy. The majority of solar energy does not reach the Earth's core; rather, it interacts with the atmosphere and surface. While some energy is indeed radiated back into space, it does not account for half of the energy; instead, it's part of the energy budget that includes absorption by the Earth and re-radiation as infrared energy. Finally, although plants do utilize solar energy for photosynthesis, they do not consume all of the solar energy that reaches Earth. Thus, the primary fate of solar energy as it interacts with the atmosphere underscores the significance of the energy absorption and reflection processes.