Natural Science CLEP Prep Practice Exam

The source of energy driving the water cycle is

1. Gravity

2. Temperature

3. Salinity

4. Sunlight

The correct answer is: Sunlight

This is because sunlight is the primary source of energy for the water cycle. While gravity, temperature, and salinity all play important roles in various aspects of the water cycle, they do not directly drive the cycle like sunlight does. Gravity helps to pull water down through the water cycle, but it does not provide the initial energy needed to start the cycle. Temperature affects the rate of evaporation and condensation, but it is not the source of energy itself. Salinity plays a role in causing density differences in the ocean, which can impact ocean currents and ultimately the movement of water in the water cycle, but it is not the source of energy that drives the cycle. Therefore, sunlight is the correct answer as it is the primary source of energy that fuels the continuous process of evaporation, condensation, and precipitation in the water cycle.