The Earth’s Surface
Investigation One introduces students to the relationship between rocks and minerals. It allows students to observe the physical properties of rock samples. Students learn that rocks have specific physical properties, but that rocks can appear different in appearance and in composition. Students will observe a collection of rocks and minerals and will observe the many different types of minerals that give rise to different rocks.
In Investigation Two, students observe the physical properties of rock samples in comparison to other solids: wood, plastic, and metal. Through these observations, students discover that the relative weight and appearance of the samples does not necessarily depend on the composition of materials alone. That is, only by considering the combination of properties, can students correctly identify a substance.
During Investigation Three, students observe and compare the particle size and appearance of rocks, sand, and soil. Students learn that the process of weathering can result in smaller rock pieces such as pebbles, gravel, sand, and soil. Students learn that organic matter such as twigs, leaves, and the remains of animals, contributes to the composition of the soil.
Investigation Four allows students to discover differences between rocks, soil, and sand in terms of their ability to absorb water. Through the creation of models and through conducting experiments, students quantify the absorbent properties of each sample.
During Investigation Five, students will examine percolation and runoff by creating a model of two types of ground surfaces. By measuring the weight of the samples before and after water is added, and by measuring the resultant runoff, students may conclude that soil has important absorbent properties but that should these be exceeded, a runoff will occur.