• Due to an explosion that took place 4.5 billion years ago, the earth broke off.
• Initially, it was a hot white mass consisting of dust and gas.
• Gradually, the dust and gas subsided and condensed into solid rocks.
• Due to the condensation and shrinking, the earth heated up.
• The solid rocks melted as a result, into liquid.
• After millions of years, the earth’s outer surface cooled and formed hard rock again.
• The inner code, however, remained hot.
• Crust was formed as a result of cooling and hardening of the molten rock and gas.
• Due to cooling, the crust became hard and thus our land was formed.
• Cooling also helps in condensation of water vapor, present in the atmosphere.
  • This resulted in the formation of seas as water vapor condensed and filled depressions on the earth’s surface.

Evolution of Earth

Initially, planet earth was composed of barren, rocky and hot molten rock. There was a thin atmosphere which was composed of Helium and Hydrogen.

Due to processes explained above, the planet was formed. A conducive atmosphere was formed which helped in the existence of life.

If we compare the density of various layers of earth, it differs. For example, while the atmosphere has a very low density, as we start going from the surface to deeper depths, the characteristic of material and its density changes.