Which explanation accounts for where rocky planets formed?

The rocky planets form closer to their star. This is due to the stronger gravitational pull by the star they are orbiting around. Even though they receive more heath, and it seems that they will be the ones that are gassy planets, because they are close to their star, they are orbiting with bigger speed, that makes their surface cool off, and thus create a rocky surface, or can be totally rocky if their core has stopped it's activity. 

The study of where things are 

Answerepicenter;