Original Project
Atoms, Molecules, and States of Matter
All atoms and molecules are in constant motion.
Item AM033003: Ice is harder than liquid water because the molecules of ice are linked more tightly together than the molecules of liquid water.
Why is ice harder than liquid water?
- The molecules of ice are not moving.
- The molecules of ice are linked more tightly together.
- The molecules of ice are harder than the molecules of liquid water.
- The molecules of ice are made of solid atoms, and the molecules of liquid water are made of liquid atoms.
(Modified from Smith et al, 2004)
- Distribution of Responses
- Students Responding Correctly
| Group | Correct | Total | Percent |
|---|---|---|---|
| Overall | 2077 | 3845 | 54% |
| Grades | |||
| 6–8 | 1395 | 2808 | 50% |
| 9–12 | 675 | 1028 | 66% |
| Gender | |||
| Male | 1004 | 1912 | 53% |
| Female | 1055 | 1899 | 56% |
| Primary Language | |||
| English | 1874 | 3412 | 55% |
| Other | 177 | 384 | 46% |
- Disciplinary Core Ideas
- PS1.A In a liquid, the molecules are constantly in contact with others; in a gas, they are widely spaced except when they happen to collide. In a solid, atoms are closely spaced and may vibrate in position but do not change relative locations.
- NRC Framework
- PS1: Matter and Its Interactions. The states (i.e., solid, liquid, gas, or plasma), properties (e.g., hardness, conductivity), and reactions (both physical and chemical) of matter can be described and predicted based on the types, interactions, and motions of the atoms within it.