Memory Mixtures and Soil MemoryVersion en ligne Match the vocabulary word to the definition. par Michael Porter soil clay To be slowly broken down by the natural processes that destroy a plant or body silt The largest particles of rock that make up soil A mixture of water, air, tiny pieces of rock, and humus The breaking down of rocks on Earth’s surface into smaller pieces physical property topsoil The upper layer of soil in which plants have most of their roots Particles of rock that are smaller than sand but larger than clay decay weathering humus mixture The smallest particles of rock that make up soil a combination of two or more different substances that keep their identities the remains of decayed plants or animals in the soil sand A characteristic of matter that you can observe or measure directly