Original Project
Substances, Chemical Reactions, and Conservation of Matter
Item SC057008: Two solids with the same melting point and color could be the same substance. (This item uses a table that lists properties of the solids.)
A student makes some observations about three solids and summarizes the results in the table below.
| Mass | Melting Point | Color | |
| Solid 1 | 3.0 g | 776°C | white |
| Solid 2 | 3.0 g | 445°C | white |
| Solid 3 | 9.8 g | 445°C | white |
Could any of the solids be the same substance and why?
- Solids 1 and 2 could be the same substance. Even though they do not have the same melting point, they have the same mass.
- Solids 2 and 3 could be the same substance. Even though they do not have the same mass, they have the same melting point and color.
- Solids 1, 2, and 3 could all be the same substance. Even though they do not all have the same mass and melting point, they have the same color.
- Solids 1, 2, and 3 cannot be the same substance because they have different combinations of color, melting point, and mass.
- Distribution of Responses
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 1256 | 2433 | 52% |
| Grades | |||
| 6–8 | 559 | 1210 | 46% |
| 9–12 | 693 | 1215 | 57% |
| Gender | |||
| Male | 624 | 1181 | 53% |
| Female | 614 | 1210 | 51% |
| Primary Language | |||
| English | 1093 | 2115 | 52% |
| Other | 137 | 268 | 51% |
- Disciplinary Core Ideas
- PS1.A Each pure substance has characteristic physical and chemical properties (for any bulk quantity under given conditions) that can be used to identify it.
- NRC Framework
- Patterns: …objects can be classified into groups on the basis of similarities of visible or microscopic features or on the basis of similarities of function…