2) The second is that whether individual atoms compose an object depends on only the intrinsic qualitative properties of each of those atoms and the ways those atoms are (restrictedly) interrelated.
the current features of and interrelations among the atoms that now compose me).
Let's also suppose that at the very first instant at which P has lost her left index finger, the atoms that at that moment come to compose P remain just as they were--intrinsically and in all their restricted atom-to-atom relations--immediately before the finger is removed.
Suppose for reductio that those atoms did compose an object.
But those atoms, if there was no finger-complement, failed to compose some further object.
If P loses her left index finger, certain atoms compose a left-index-fingerless person (presumably P).
It seems plausible to suppose that, at the first instant that the atom fails to exist, the atoms that then compose P have not yet reacted to the change.
First, it is possible that after the annihilation of one of the atoms that compose a person P, a person exists who is composed of the atoms that originally composed P except the annihilated one.