For Mass changes when a reactant or product is a gas, which answer check answer best supports this Unit 4.3 objective: Link gas escape or gas uptake to whether mass appears to decrease or increase in an open apparatus?

The correct option is The mass increases.

The correct option is The mass increases. The mass increases is correct because it directly supports the approved learning objective to link gas escape or gas uptake to whether mass appears to decrease or increase in an open apparatus. This answer check variant asks students to separate gas from similar Unit 4.3 calculation steps. The reasoning belongs to Mass changes when a reactant or product is a gas within Chemical measurements, conservation of mass and the quantitative interpretation of chemical equations, so it should not be confused with nearby quantitative ideas such as mass, moles, concentration, yield, atom economy, or gas volume unless those are named in the objective. Use the focus term gas to keep the answer aligned with AQA GCSE Chemistry 8462 Unit 4.3. The other options are weaker because they either use the wrong formula, the wrong unit, a vague relationship, or the wrong quantitative context.