Item AM046006: During a hot day in the summer, the spaces between the concrete sections of a sidewalk get narrower because the concrete sections expand.

Most sidewalks are made out of solid concrete sections. There are spaces between the sections. What happens to the spaces during a hot day in the summer and why?

  1. The spaces get wider because the concrete sections shrink.
  2. The spaces get narrower because the concrete sections expand.
  3. The spaces stay the same because the concrete sections does not shrink or expand.
  4. Some spaces get wider, some spaces get narrower, and some spaces stay the same because each concrete section behaves differently on a hot summer day.
(Modified from Berkheimer, et al., 1988)

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