Answer:
1. Roche limit
2. hydrogen
3. atmosphere
4. Mercury
5. Venus
6. When an object passes the Roche limit, the strength of gravity on the object increases. If the density of the planet is higher, then the object can break up farther away from the planet. If the density is lower, then the Roche limit is located closer to the planet.
7. Farther out in the solar system, beyond the frost line, hydrogen was at a low enough temperature that it could condense. This allowed hydrogen to accumulate under gravity, eventually forming the Jovian planets.
Explanation: