What are three examples of how the nebular theory explains some observed features of the present-day solar system?
The direction of the rotation, the plane of rotation, the lighter planets further from the center of rotation.
All of the planets rotate in the same direction. This can be explained by the nebular disk spinning in all the same direction.
All of the planets rotate is essential the same plane of rotation.
This can be explained by the disk being a flat disk that formed the planets.
The outer planets are made of lighter materials like frozen gases and the four inner planets are made of more dense material. This can be explained by the rotational momentum causing the lighter material to be "thrown" further out to the outer planets,
On the other hand the nebular theory would predict that the sun with 99% of the mass of the solar system should have 99 % of the rotational momentum. But the empirical evidence is that the sun has only 1 % of the rotational momentum.
The comets enter the solar system at an extreme angle that doesn't match the rest of the solar system (Also the comets seem to be much younger than predicted by the nebular theory)
The nebular theory was proposed by Emanuel Kant a philosopher not a scientist. The theory was proposed for philosophical reasons ( material realism ) not empirical evidence.