Video narration
How do scattered bits of material become a planet? Think of crumbs gathering into a clump. It's only a rough comparison: in space, gravity and collisions do the work. Around the young Sun, dust and rocky bits circled. As they collided, some joined into larger bodies. Those bodies pulled in more material through gravity, and further impacts kept building them up. Earth did not appear as a finished world in one instant. Many smaller pieces built it over time. Each collision released heat. The growing Earth became intensely hot, and its materials began to separate: heavier material sank toward the center, while lighter material stayed nearer the outside. That is how the young world developed layers. So how did scattered bits become Earth? Dust and rock gathered around the young Sun, and gravity and repeated collisions built them into a hot, layered planet.