Final answer:
Soil particles that are 0.1 to 2 mm in diameter are known as sand. These particles are part of the soil profile, which includes layers of differing materials including sand, silt, and humus.
Step-by-step explanation:
Soil particles that are 0.1 to 2 mm in diameter are called sand. The soil profile refers to a vertical section of soil from the surface to the bedrock, showing all the layers of materials. The outer loose layer that covers the surface of Earth is known as soil, and within this layer, particles of different sizes can be found. Silt soil particles range in size between 0.002 and 0.1 mm in diameter, which is smaller than sand but larger than clay particles.
These particles make up the constitution of the soil along with organic matter like humus, which is composed of decaying plants and animals and helps to improve soil structure and fertility. In contrast, particles of clay are even smaller, less than 0.002 mm in diameter.