Question

A student hypothesizes that melting ice decreases the total mass of water molecules. The graph below shows their data.




Responses

A The hypothesis is valuable because it showed that matter is lost during melting and no further testing is required.The hypothesis is valuable because it showed that matter is lost during melting and no further testing is required.

B The hypothesis is valuable because it showed that mass is always reduced when substances change state and no additional investigation is needed.The hypothesis is valuable because it showed that mass is always reduced when substances change state and no additional investigation is needed.

C The hypothesis is valuable because it demonstrated that physical changes conserve mass and can lead to new investigations. The hypothesis is valuable because it demonstrated that physical changes conserve mass and can lead to new investigations.

D The hypothesis is valuable because the data proved no further study should be conducted since the results did not support the claim.

Answer 1

C

The data show mass did not decrease when the ice melted, so the hypothesis was disproven. That outcome is still valuable: it demonstrates that physical changes (melting) conserve mass and suggests further investigations (e.g., measurement precision, open vs. closed system, slight mass loss by evaporation).