Science: The Water Cycle: Challenge

# Hard Level Guide Stretch thinking with multi-step problems, application questions, and deeper reasoning. # Water on Earth Most of Earth's water is in oceans. Water also exists in lakes, rivers, ice, groundwater, and the atmosphere. The same water has been cycling for billions of years. The sun provides energy that drives the water cycle. # Evaporation and Transpiration Evaporation changes liquid water into water vapor when the sun heats oceans, lakes, and puddles. Plants release water vapor through transpiration. Together, these processes move water from Earth's surface into the air. # Condensation and Clouds When water vapor cools high in the atmosphere, it condenses into tiny droplets around particles. Millions of droplets form clouds. Fog is condensation near the ground. Condensation releases heat energy. # Precipitation and Collection When droplets combine and grow heavy, they fall as rain, snow, sleet, or hail. Water collects in oceans, rivers, lakes, and soil. Groundwater may take years to return to the surface. The cycle then begins again.