Rocks and Soil
Grade 2 · Science · Study Guide
Discover what rocks and soil are made of and why they are important.
Rocks are hard, solid objects found in the ground, in rivers, and on mountains. Rocks come in many different sizes, shapes, and colors. Some rocks are very small, like pebbles. Others are huge, like boulders. Rocks are made of minerals, which are natural materials found in the earth.
Rocks can be smooth or rough. Water in rivers tumbles rocks together for many years, making them smooth. Rocks that have not been worn down are often rough and have jagged edges.
Over a very long time, rocks can break into smaller and smaller pieces. Wind, water, and ice help break rocks apart. When rocks break into tiny pieces and mix with dead plants and animals, they form soil.
Soil is the loose material found on top of the ground. Plants grow in soil because it has nutrients, or food, that plants need. Soil also holds water that plants drink through their roots.
There are different kinds of soil. Sandy soil has large pieces and does not hold much water. Clay soil has very tiny pieces and holds a lot of water. Good garden soil, called loam, is a mix of sand, clay, and material from dead plants.
Rocks and soil are very important to life on Earth. Animals live in soil, plants grow in it, and it helps clean our water.
Key terms
- rock
- A hard, solid natural material made of minerals found in the earth
- mineral
- A natural material found in the earth that makes up rocks
- soil
- The loose material on top of the ground made of tiny rock pieces and decayed plant matter
- erosion
- The wearing away and moving of rocks or soil by wind or water
- nutrients
- Materials in soil that plants need to grow and stay healthy
- texture
- How a surface feels, such as rough or smooth
Flashcards
- rock
- A hard natural material made of minerals
- mineral
- A natural solid material that makes up rocks
- soil
- Loose material on top of the ground where plants grow
- pebble
- A small, smooth rock
- boulder
- A very large rock
- erosion
- The wearing away of rocks or soil by wind or water
- nutrients
- Materials in soil that help plants grow
- loam
- A rich mix of sand, clay, and plant matter — great for growing plants
Questions
What are rocks made of?
- Minerals
- Soil and sand
- Dead plants
- Ice and water
Show answer
Answer: Minerals
Rocks are made of minerals, which are natural solid materials found in the earth.
Soil is made partly from broken pieces of rock.
Show answer
Answer: True
When rocks break into tiny pieces over time and mix with dead plant material, they form soil.
Plants grow in soil because it has ________ that help them grow.
Show answer
Answer: nutrients
Soil contains nutrients, which are materials that plants need to grow healthy and strong.
What kind of soil holds the most water?
- Sandy soil
- Rocky soil
- Clay soil
- Loam soil
Show answer
Answer: Clay soil
Clay soil has very tiny particles that pack tightly together and hold a lot of water.
All rocks are the same color and shape.
Show answer
Answer: False
Rocks come in many different colors, shapes, sizes, and textures.
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