Question

1. why is rain not part of the atmosphere?

because it is part of the lithosphere
because it is part of the biosphere
because it is part of the hydrosphere
because it moves between spheres

Explanation:

Rain is water in liquid form. The hydrosphere encompasses all water on Earth, including liquid water like rain. The lithosphere is the rocky outer part of the Earth, the biosphere is the global sum of all ecosystems, and while water (including rain) can move between spheres (as in the water cycle), the key classification here is that rain is water, so it belongs to the hydrosphere.

Answer:

because it is part of the hydrosphere