Original Project
Substances, Chemical Reactions, and Conservation of Matter
Item SC045004: Two liquids undergo a chemical reaction in an open jar and bubbles form. The mass of the liquids is less after the reaction because some atoms went into the air.
A student has two different liquids in open jars. She pours the liquid from one jar into the other jar, and she observes bubbles. After the bubbling stops, she finds that the total weight of the liquids is now less than the total weight of the liquids before they were mixed together.
How can her observation be explained?
- Some atoms went into the air.
- Some atoms were destroyed.
- Some atoms became heavier.
- Some atoms became lighter.
- Distribution of Responses
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 1230 | 2723 | 45% |
| Grades | |||
| 6–8 | 630 | 1613 | 39% |
| 9–12 | 589 | 1089 | 54% |
| Gender | |||
| Male | 604 | 1301 | 46% |
| Female | 598 | 1367 | 44% |
| Primary Language | |||
| English | 1100 | 2396 | 46% |
| Other | 97 | 260 | 37% |
- Disciplinary Core Ideas
- PS1.B Substances react chemically in characteristic ways. In a chemical process, the atoms that make up the original substances are regrouped into different molecules, and these new substances have different properties from those of the reactants.
PS1.B The total number of each type of atom is conserved, and thus the mass does not change.