Test the top two or three methods if possible. Students will record the name of the sample and whether it is acidic, basic, or neutral. Enrichment Discuss with students how large increases in concentrations of nitrates from agricultural runoff results in algae bloom and ultimately enormous fish kills. Discuss interrelationship of nitrates, dissolved oxygen, turbidity, and different photosynthetic activity during day and night. Closure Students each write down three things they learned during this lesson.
Student share their thoughts, with the teacher keeping tally of the most common ideas.
Follow up by probing students to try and discover if the new knowedge conflicted with previous understanding of concepts. For each Guided Practice activity, students will record data and answer two or three questions. Students will be observed in the field for demonstration of proper and safe technique for measuring dissolved oxygen and other parameters. Given a water sample and appropriate lab supplies and equipment, students measure pH and temperature. Students will demonstrate proper, safe lab technique and express values in appropriate units.