Conservation of mass in environmental systems is the focus of this Grade 7 Science resource within Matter and Chemical Change. Students examine how mass is conserved in closed and near-closed systems, use mass-balance reasoning, and distinguish a true change in mass from the redistribution of matter.

What Students Explore

The resource connects the law of conservation of mass to practical science investigations. Students reason about measured and expected masses, consider how reaction stoichiometry and waste accounting depend on conservation of mass, and evaluate observations from closed or near-closed systems.

Key vocabulary is used in context, including closed system, atoms, reactants, and products. Students also examine evidence that can show whether mass has actually changed or has simply been redistributed within a system.

Question and Activity Mix

Students work through multiple-choice questions, true-false questions, short-answer responses, a reading passage, a matching activity, a cloze passage, an essay, and a “did you know” section. This combination gives students opportunities to recognize concepts, interpret scientific situations, apply conservation-of-mass reasoning, and communicate their thinking.

Included Teacher Supports

• ✅ Student Notes & Lesson Summary supplement for reinforcing key ideas and vocabulary
• ✅ Separate Teacher Guide PDF with learning objectives and teaching tips
• ✅ Discussion questions to support classroom conversation
• ✅ Common mistakes section to help address likely misconceptions

Classroom Use

Use this Grade 7 conservation of mass worksheet as guided practice during a Matter and Chemical Change lesson, independent work, review, or a science assessment opportunity. The practical scenarios make it possible for students to apply mass-balance reasoning rather than simply recall the law.

The resource is identified with the Alberta framework and gives teachers a focused way to address conservation of mass while connecting physical and chemical changes with observations, reactants, products, and environmental-system accounting.