Question

multiple choice question
atoms of different chemical elements can be differentiated based on the number of
neutrons in the nucleus
electrons in all shells
protons in the nucleus
orbitals in the outermost shell
electrons in the outermost shell

Explanation:

Each chemical element is defined by the number of protons in its atomic nucleus, called the atomic number. This number is unique to each element, while neutrons can vary (isotopes), and electron counts change in ions.

Answer:

C. protons in the nucleus