Question

a student is investigating a sweet food and a jar containing a sour food. the image above shows the sweet and sour foods. at room temperature, these foods are solids. the same amount of energy was transferred into both substances. one food had changed phase while the other had not. which food changed phase, and how did it change?
a) the sweet food changed because the molecules were able to move fast enough to overcome the attraction between them. its molecules now move away from each other.
b) the sweet food changed because the strong attraction between molecules made their movement slower. its molecules now move around each other.
c) the sour food changed because the weak attraction between molecules let them move faster. its molecules now move away from each other.
d) the sour food changed because the molecules were able to move fast enough to overcome the attraction between them. its molecules now move in place.

Explanation:

To determine the correct answer, we analyze the phase change of the sour food. When energy (heat) is transferred, molecules' motion and intermolecular attractions are key. For a phase change (likely melting or softening), molecules need enough energy to overcome attractions. Option d states the sour food changed because molecules moved fast enough to overcome attraction, new molecules move in place (consistent with phase change, e.g., from solid to semi - solid/liquid where molecules gain enough kinetic energy to move more freely, overcoming intermolecular forces). Other options: a says molecules moved away (incorrect for typical food phase change like softening), b says strong attraction slowed movement (opposite of what happens with energy input), c says weak attraction made them move faster (weak attraction alone doesn't explain, it's about overcoming attraction with energy - driven faster motion).

Answer:

d. The sour food changed because the molecules were able to move fast enough to overcome the attraction between them. Its molecules now move in place.