Earth is made up of three main layers :-
1. Crust:-we live on the outer part of the earth which is called the crust. this layer goes up to a depth of 100kms. this layer consists of rocks.
2. Mantle:-it is 100-2,900kms in thickness. the upper part of the mantle is a pliable layer over which the crust floats. this consists mainly of chemicals called silicates.
3. Core:-the core is 2,900 to 6,376kms in thickness. it is composed of dense and heavy substances like iron and nickel. it can be divide into two sub layers.
a) Outer Core:- 2,900 to 5,100kms composed of liquid like metallic material like nickel and iron.
b) Inner Core:- the solid inner core(5,100 to 6,376kms) of the earth is made up of iron compounds and heavy substances like gold.