Question

What is earth made of? How does earth’s composition compare to other planets?

Answer 1

Hint: Earth is a unique planet. It is composed of various minerals and gases. It has an abundance of water. Some other moons and planets are also found to be having water and atmosphere but as far as we know only earth has the right composition of the right amount of water and minerals to sustain life.

Complete answer:
Earth contains many elements. Some we have discovered and some maybe yet to be discovered. Earth is composed of many minerals and gases. It has various layers and each layer has a different composition.
 We can vaguely divide Earth into three layers.

-CRUST: It is the outermost layer of the Earth. We live on this layer. Soil is the topmost layer of the crust. The thickness of the Crust can vary from place to place. It is around 5Km of thickness on the ocean floor. And it is about 70Km thick on the land. This layer is mainly rich in minerals as we know that it contains rocks which are primarily made up of silica and almunia.

-MANTLE: The layer beneath the Crust is Mantle. It is upto 2900Km thick. It contains solid rock which is rich in magnesium and hot dense iron.

-CORE: This is the centre of the earth. It is made up of two layers: - The outer core and the inner core. The outer core is liquid and is made up of iron, nickel and molten rocks. The temperature of the core is very high which can be upto 50,000 degree Celsius. The inner core of the earth is solid. It is mostly made up of iron. This Iron in the inner core is said to be responsible for Earth’s magnetic movement.
The Atmosphere of earth separates it from other planets. Also the minerals present on the Crust i.e. the outer layer of earth helps it to sustain life. Unlike other planets earth atmosphere is oxidizing. Earth's atmosphere contains about 78% nitrogen and 21% oxygen. And traces the amount of various other gases and moisture. Whether in other planets like Venus there is about 96% of carbon dioxide. This shows that the atmosphere is reducing in nature which can also mean that the water is most likely to be in gaseous state on these planets. So having an oxidizing atmosphere helps earth to have water in liquid state and also help in sustaining life. Other than water the minerals present on the outer surface of the earth also helps in growing plants. All these factors help in sustaining life on earth.

Note: Earth’s atmosphere was not always oxidizing in nature. The atoms present at the beginning were mainly hydrogen and helium which were around 92%. All the other elements are a result of nuclear fusion between these two atoms. It takes billions of years for the earth’s atmosphere to be able to sustain life.