Teacher Monitoring Guide
Grade 7 · Cycle 2 · Week 2 — Conservation of Mass
in Chemical Reactions
Learning Goal
Students will analyze and interpret data to support the claim that atoms
are conserved during chemical reactions, and balance simple chemical
equations to demonstrate this conservation.
Station Checkpoints
Station 1 — Hook & Phenomenon
Look for: Students connecting the phenomenon to prior knowledge and
generating testable questions
Common misconception: Mass can be created or destroyed during a reaction
if a gas escapes — use sealed container data to show total mass is
conserved
Station 2 — Investigation / Data Collection
Look for: Accurate data recording and identification of emerging
patterns in the evidence
Common misconception: Balancing an equation changes the substances —
clarify that coefficients show amounts, not formulas; subscripts define
the substances
Station 3 — Sense-Making
Look for: Students revising their model based on evidence collected
during investigation
Common misconception: Conservation of mass only applies to solids and
liquids — extend to gaseous products and reactants using closed system
measurements
Exit Ticket Monitoring
| Score Range |
Interpretation |
Next Step |
| 18–23 pts |
Meeting target |
Extend with synthesis question |
| 10–17 pts |
Developing |
Small group re-teach at day start |
| 0–9 pts |
Needs support |
1:1 intervention before next station |
MTSS Tier 2 Supports
For students scoring below 10 pts on the exit ticket: use the sentence
frames below during the next class's hook.
- "I notice that _____ because _____."
- "The evidence shows _____, which means _____."