# Use an Apple to Model the Earth

The circular shape and structure of an apple and the ease of slicing it makes it an excellent model to understand the earth and its various structural components. As an interactive learning tool, consider using an apple to teach kids about the different layers of the earth and encourage learning in the fun and memorable way!

## Skin of an Apple as the Crust

At the onset, when the earth’s center became molten, the lighter compounds started to rise towards the surface, forming the brittle crust. Along with the top part of the mantle – the next layer of the earth – the crust formed a hard slab like layer called the lithosphere which is what we know as the ‘crust of the earth’.

The crust of the earth is very thin compared to the other two layers, much like the skin of an apple. It lies over the mantle and is mostly composed of igneous, metamorphic, and sedimentary rocks and occupies less than 1% of the earth’s volume.

The earth’s crust is only 8km thick under the oceans and 32 km thick under the continents. The crust can be broken into small pieces called ‘plates’ that float on the soft, plastic mantle – similar to the fleshy part of an apple.

## Apple Pulp as the Mantle

Have you noticed that the fleshy part, nearest to the core of an apple, is a little softer than the rest of it? It is very similar to the earth’s mantle. The mantle of the earth is found between the crust and core of the earth, just like the pulp of an apple. It is mainly composed of solid rocks and a semi-solid layer near the core called magma. The mantle is the largest layer of the earth measuring almost 2800km in thickness.

## Core of an Apple is Similar to the Core of the Earth

The core of an apple is similar to the outer and inner cores of the earth. The core is like a little round ball in the middle of the earth, very similar to the seed in the depths of an apple. The outer core of the earth is composed of nickel and iron in liquid form because of the excess heat. The innermost layer of the core also composes of nickel and iron but in a solid form because of excessive pressure from the rest of the layers.

When teaching kids new science based concepts, it is always helpful to make fun comparisons like this one to introduce kids to topics like the layers of the earth.