Kara built a model of how molecules behave when they are in solid form. She filled a clear plastic box with marbles to the very top and put the lid on the box. When she shakes the box, the marbles can barely move.

Question

Which of the following is a limitation of Kara's model?
A.
The marbles are made out of atoms, but molecules are not.
B.
The marbles have limited motion, but molecules in solids move a lot.
C.
The marbles must be held in a box, but solids hold together without a container.
D.
The marbles are all the same shape, but molecules all have unique shapes.

Answer 1

The best answer to the question about the limitation of Kara's model is:

C. The marbles must be held in a box, but solids hold together without a container.

This option highlights a significant difference between the model (marbles in a box) and the actual behavior of solid molecules, which do not require a container to maintain their structure.