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Maintaining Mass Lesson Overview

Students will first view and then hypothesize, based on their knowledge of the law of conservation of mass, why a teacher demonstration does not seem to prove the law. Students will then explore a modified version of the experiment to determine ways that the teacher demonstration should have been changed to show conservation of mass effectively.


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90 Minutes
Whole Class, Pairs
PTI Inquiry
1.1, 1.3, 2.4, 2.5, 3.1, 5.2, 5.8, 6.1, 7.3
Lesson Components Time Inquiry Skills Tech. Used Engage Level Brief Description
Engage 10 min 1.3, 5.2 Projector, YouTube 3 Students will view time lapsed videos of both a building being built and a plant growing and will answer questions about their observations.
Explore 30 min 1.1, 2.5, 3.1 Document Camera, Digital Scales 3 Students will observe a teacher demonstration and then complete an experiment to show evidence of conservation of mass during a chemical change of matter.
Explain 20 min 7.3 none 2 Students will compare and contrast the two experiments and answer questions, discussing their answers and additional observations with the class.
Expand 20 min 6.1, 2.4, 5.8 Digital Scales 3 After creating a plan, students will modify teacher demonstration to make it properly describe conservation of mass.
Evaluate 10 min   none 1 Students will answer 5 assessment questions related to evidence of conservation of mass.

Level of Student Engagement
1     Low     Listen to lecture, observe the teacher, individual reading, teacher demonstration, teacher-centered instruction
2     Medium     Raise questions, lecture with discussion, record data, make predictions, technology interaction with assistance
3     High     Hands-on activity or inquiry; critique others, draw conclusions, make connections, problem-solve, student-centered

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