Section 1
Earth Distributes Fresh Water Unevenly
Only about 3% of Earth's water is fresh water, with much of it frozen at the poles. Running water, standing water, and groundwater provide most usable fresh water for humans.
Grade 5 students explore air and water as essential Earth resources in this lesson from Chapter 4 of Science: A Closer Look, learning about the distribution of fresh water versus salt water on Earth and key terms including reservoir, aquifer, smog, and ozone. Students investigate sources of fresh water such as rivers, lakes, reservoirs, and aquifers, and discover why ocean water is salty. A hands-on inquiry activity has students measure and calculate their own daily fresh water usage, then design data tables to compare results with classmates.
Section 1
Earth Distributes Fresh Water Unevenly
Only about 3% of Earth's water is fresh water, with much of it frozen at the poles. Running water, standing water, and groundwater provide most usable fresh water for humans.
Section 2
Communities Clean Water Through Treatment Plants
Water treatment plants clean fresh water through several steps: coagulation captures dirt, sedimentation lets particles settle, filtration removes remaining particles, and disinfection kills harmful bacteria.
Section 3
People Conserve Water Through Daily Choices
People can save water by taking shorter showers, fixing leaks, running full loads of laundry and dishes, watering plants after dark, and turning off faucets when not in use.
Section 4
Air Pollution Damages Earth's Protective Layers
Pollutants from burning fossil fuels create smog, while chemicals in aerosols harm the ozone layer. Natural events like volcanic eruptions also release harmful particles into the atmosphere.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter
Expand to review the lesson summary and core properties.
Section 1
Earth Distributes Fresh Water Unevenly
Only about 3% of Earth's water is fresh water, with much of it frozen at the poles. Running water, standing water, and groundwater provide most usable fresh water for humans.
Section 2
Communities Clean Water Through Treatment Plants
Water treatment plants clean fresh water through several steps: coagulation captures dirt, sedimentation lets particles settle, filtration removes remaining particles, and disinfection kills harmful bacteria.
Section 3
People Conserve Water Through Daily Choices
People can save water by taking shorter showers, fixing leaks, running full loads of laundry and dishes, watering plants after dark, and turning off faucets when not in use.
Section 4
Air Pollution Damages Earth's Protective Layers
Pollutants from burning fossil fuels create smog, while chemicals in aerosols harm the ozone layer. Natural events like volcanic eruptions also release harmful particles into the atmosphere.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter