Solar system model. who proposed this model? what do you observe?

The Solar System model that changed the view of the people about the Earth and the other objects in the sky was proposed by the Polish astronomer Nicolai Copernicus in the 16th century.

Copernicus, by observing the sky and the objects on it, managed to get to a conclusion that drastically differed from the viewpoint that was in place for almost 2,000 years. He proposed that the Earth is actually not the center of the universe, but that that position is held by the Sun, while the Earth and the other planets are spinning around the Sun.

In the Solar System model we can observe the Sun as the largest object, situated in the middle, being static. All the other planets, including the Earth, are spinning around the Sun. The Moon on the other hand is spinning around the Earth, being the only object to do so, but it is also spinning around the Sun as the other objects.

fe 55.85 g/mol and h2o 18.02 g/mol.

i do not get it   at all