Answer:
D (hope I’m right, sorry if it’s not)
1p is not possible because it goes like this 1s2 2s2 2p6
A. An oxidation state is a number that is assigned to an element in a chemical combination. This number represents the number of electrons that an atom can gain, lose, or share when chemically bonding with an atom of another element.
For the first question nail rusting is not an example of physical change