Science Encyclopedia for Kids

THE EARTH'S LAYERS - The Inner and Outer Core, The Mantle, The Crust

The part of the Earth we live on is solid, but the inside of the Earth is very different. Earth has four different layers: the inner core, the outer core, the mantle, and the crust. When the Earth was formed, the heaviest materials sank to the center. These materials formed the Earth's core. They share the same name, but the inner and outer core are very different. The thickest part …

1 minute read

SOIL - The Lithosphere, Soil Horizons, Soil Composition, Particle Types and Soil Textures

Have you noticed that the Earth is hottest at the core and gets cooler as we reach the crust? Because it has cooled, the rock near the Earth's surface is hard and solid. We call this layer of hardened rock the lithosphere. The lithosphere is made up of the crust and upper mantle. Think of it as the layer of solid rock that makes up the hard shell of the Earth. In the same way, the hydrosph…

4 minute read

TYPES OF ROCKS - Igneous Rocks, Sedimentary Rocks, Metamorphic Rock

We all know a rock when we see one. But what makes something a rock? By definition, a rock is a mass of mineral matter. A mineral is a naturally occurring crystalline substance. There are thousands of different types of minerals. Some minerals you may know include salt, coal, copper, quartz, and talc. A quartz cluster. Think of rocks as a meal, and the minerals as the ingredients that make …

2 minute read

LAND FORMATION - Constructive Forces, Folding, Faults, Magnitude and Effect, Volcanic Eruptions, Deposition of Sediment, Destructive Forces, Weathering, Erosion

You may not realize it, but the land is changing all the time. The Earth is always working to build new land and to wear down the old. Sometimes changes to the Earth happen rapidly, but other changes can take millions of years! The processes for building new land are called constructive forces. Three of the main constructive forces are crustal deformation, volcanic eruptions, and deposition of s…

6 minute read


It's hard to think of rocks as moving objects unless you pick one up and throw it! But rocks do move—slowly— as they are created, destroyed, and changed into new types of rock. The way rocks change over time is called the rock cycle. The rock cycle takes place over a very long period of time. It may take millions of years for a rock to change from one type to another. Underst…

1 minute read

THE SECRETS IN ROCKS - Just how old is the Earth?

You might not think that something as ordinary as a rock could hold great secrets. Scientists know that by studying rocks, they can discover many hidden things about our planet. A lot of information comes from sedimentary rock. As you know, sedimentary rock is formed in layers over millions of years. Looking at each layer is like looking at a different period in history. Sedimentary rock laye…

1 minute read


constructive forces (con-STRUK-tiv FORSS) — processes by which rock is created, such as crustal deformation, volcanic eruptions, and deposition of sediment core (KOHR) — the Earth's center, it is made of an inner core and an outer core crust (KRUHST) — the outer layer of the Earth crustal deformation (KRUS-tull dee-for-MAY-shun) — when the shape of land (or crus…

1 minute read

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