Groundwater is contained in the zone of saturation below the land surface. The top of this zone is known as the water table. People can tap into this source of water by drilling wells. The depth of the well and level of the water table greatly influences the wells productivity. In this activity you will demonstrate the relationship of groundwater to wells.

The ocean is a “carbon sink,” which means that it removes CO₂ (carbon dioxide) from the atmosphere. The ocean currently absorbs about one-third of the CO₂ released by the burning of fossil fuels.

However, beyond a certain level of atmospheric CO₂, the ocean can no longer act as a carbon sink without it having a negative impact on marine life. When CO₂ dissolves in seawater, it leads to decreased pH levels. The ocean becomes less alkaline. This is referred to as ocean acidification.

Much of the food that people eat is produced as crops grown from seeds. What does it take for a seed to grow? How does a seed start to grow? What changes occur as it grows?

Understanding the growth of seeds can help us understand food production, which is basic to understanding the issue of hunger in the world.

Materials

For each group:

Crucial to our existence, water sustains all life on Earth. Following the old adage, "What goes around comes around," water moves continuously through the stages of the hydrologic cycle (evaporation, condensation, and precipitation). How does our drinking water fit into this hydrologic cycle? Where did the water we drink fall as precipitation? Did this water percolate down into the ground as part of a groundwater system, or did it remain on the surface as part of a surface water system? What path did this water follow in order to become our drinking water? This lesson will explore the hydrologic cycle and water's journey to our glass.