How did our planet?

Our planet was formed about 5 billion years ago from a dense clouds of cosmic dust and gases, which scientists have named Protozilla. At first it was a cold lifeless concentration of cosmic matter. Gradually, under the influence of solar attraction, from impacts of cosmic bodies and due to radioactive decay of Protozilla began to heat up. Primary substance became so hot that it melts, and in the light of the compounds remained on the surface, and the heavier elements and compounds sank into the Ground. Next was the division of the earth's interior on the core and the mantle.