The Water Table Science 8 What is Water

The Water Table Science 8

What is Water? ▪ The chemical formula for water is: H 2 O. ▪ There are 2 hydrogen atoms fro every 1 oxygen atom. ▪ One part of the molecule (hydrogen) has a slightly positive charge and the other (oxygen) has a slightly negative charge.

▪ The charge causes each water molecule to act like a tiny magnet. ▪ The magnetic charge affects how water behaves underground!

The Water Table ▪ The water cycle affects how much water we have available to us: ▪ When rain strikes the ground the water molecules act like magnets to the soil causing the water to spread outward.

Importance of Percolation: ▪ Gravity pulls the water down into the earth, dissolving salts and minerals as it moves through the soil → this is percolation! ▪ Water eventually reaches the aquitard: a layer that will not allow water to pass through quickly enough to use as a water source.

Zones of the Water Table ▪ As more rain falls the layer above the aquitard becomes completely full with water. ▪ This is called the Zone of Saturation. ▪ The upper layer of the Zone of Saturation is the Water Table. ▪ Above the Zone of Saturation, is the Zone of Aeration which is found in the upper soil layers that hold both air and water. ▪ An aquifer is a large accumulation of water in soil or rock.

Zones of the Water Table

Layers of the Water Table

Water Table Questions 1. How does the chemical structure of water affect how water behaves under ground? 1. In general, how deep must a well be drilled in order to be a good source for human consumption? Explain why. 1. Describe the difference between the Zone of Aeration and the Zone of Saturation? 1. Could groundwater be polluted through a well? If so how? 1. What causes the water table to rise and fall?

Homework! Complete Questions 1 – 4 from the textbook on Page 217 for homework.