Could someone help me to say this better? I have to Distinguish between atomic physics and nuclear physics, so here is what i have.

which deals with the atom as a system of electron(s) and a nucleus and nuclear physics, which considers atomic nuclei alone

Atomic Physics is concerned with structure and properties like reactions in the atom.

while
Nuclear physics is concerned wiht the strucuture. properties aswell as reactions taking place in the nucleus of the atom.
So, we say that atomic means an atom and nuclear means nucleus. Not atoimcnuclei but only nucleaus if you are talkin gabout nucleaus that is NUCLEAR PHYSICS.
If you are talking about differences so these definitions are the best just take like.
Nuclaer physics is concerned with the nuclei of an atom.
Atomic physics is concerned with the atoms.
Nuclaer physics is concerned with the structure, properties and nuclei.

Sure! Here's a way to rephrase your statement:

Atomic physics focuses on studying the behavior of atoms, specifically examining how electrons and the nucleus interact within the atom as a whole. On the other hand, nuclear physics is concerned solely with studying atomic nuclei, without considering the presence or behavior of electrons.