Describe at least two observable differences between sand, soil, and rock, and explain that rocks slowly break down into smaller pieces like sand over time.
Sand, soil, and rock might all seem like plain dirt at first glance, but they are different Earth materials with different properties. Sand is made of small, gritty grains. Soil is usually darker and may include bits of dead leaves or other organic matter, and it clumps together when damp. A rock is one solid, hard piece.
Here is a secret connecting them all: sand is actually tiny broken pieces of rock. Over a very long time, wind, water, and weather slowly break big rocks down into smaller and smaller pieces, eventually becoming the gritty grains you find at a beach or in a sandbox.
Mastery looks like: They describe at least two observable differences between sand, soil, and rock, and explain that rocks slowly break down into smaller pieces like sand over time.
Common stumbles: Thinking sand and soil are basically the same thing; not realizing sand is actually made of tiny broken pieces of rock.