Living things exploit free energy as a resource to preserve their existence. Non-living things don’t do this: Jupiter doesn’t use gravity to maintain its size – its size (and, in fact, the only existence it has as a planet) was just an effect of gravitational attraction on clouds of gas. Saturn doesn’t use its momentum or the sun’s warping of spacetime to preserve its orbit – its orbit is just an effect of these things, uncoordinated by any logos or substantial totality of Saturn itself. Natural things are existential ciphers, being neither a stable logos nor being preserving its own existence. That these atoms now are water is not existentially different from their now splashing in a pond or orbiting in a comet. They could be anything else in the same way that they could do anything else.
This existential nullity is what allows living substances to form themselves from natural things. If the atom were a bona fide substance then the organism would be a cloud or a heap when the reverse is the case. Life takes advantage of the insubstantial character of natural elements to both elevate them and constitute itself.
The natural world does however have a borrowed substantiality. This is clear from inertia, understood to include not just the tendency of an element to preserve its state of motion or rest but also to preserve its being (setting aside for the moment the effects of entropy and atomic decay) shifting an element or a compound takes energy. The basic fact of nature is its tendency to keep whatever being it has borrowed for itself. Nature is by definition a secondary existence and activity, as Plato argues in Laws X.