A particular state of matter has atoms that are packed closely together and vibrating in fixed positions. A phase change occurs and the matter changes to a state where the atoms are spaced far apart and are moving about randomly. What can you infer has occurred?

it goes to a solid to a liquid

Explanation:

When something is a solid the molecules are impact together and have a small sense of vibration. But as the solid melts away for example ice, the molecules become more loose forming into a liquid

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.