The gas planets, in our solar system at least, are Jupiter, Saturn, Uranus, and Neptune, in order from least to greatest distance from the Sun. They are all found beyond the Asteroid Belt. The gas planets, or "Gas Giants" if you will, are larger and less dense than the other planets. They all have rings and several moons.
The Earth has the greatest average density, of all the planets.
All of the planets in the Solar System except for Mercury and Venus have at least one moon.
Yes, all the outer planets have at least a dozen moons.
From the Sun out it is: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto (a dwarf planet or plutoid).
All planets orbit around the greatest centre of mass. In our solar system, that is our Sun.
There are 184 moons in our Solar system, counting ones associated with dwarf planets. The largest moon, Ganymede, orbits Jupiter. Mars' two moons are so small that they are not even round.
Mercury and Venus have no known satellites, all other planets have at least one.
All planets have an elliptical orbit and the planets do not cross paths. They are all at least 15,000 miles around. They all have atmospheres. They all have their own gravity. They all have cores.
Saturn is the least dense planet in our solar system.
All the planets have orbits so four cannot be picked out.
The factors of 33 from least to greatest are: 1, 3, 11, 33