Final answer:
Rocks have a longer ground period compared to clay and sand.
Step-by-step explanation:
In terms of the ground period, rocks have the longest period compared to clay and sand. The ground period refers to the time it takes for a substance to become heated and cooled.
Clay and sand have shorter ground periods compared to rocks because they heat up and cool down more quickly. Clay is made up of fine particles of silt, giving it plasticity, while sand is composed of larger particles. Rocks, on the other hand, have a longer ground period due to their composition and density.