The atom's core is the central part of an atom that contains the positively charged protons and electrically neutral neutrons. There are several synonyms for the term "atom's core", including the nucleus, central nucleus, atomic nucleus, and core. The term "nucleus" is the most commonly used synonym and refers to the central region of the atom where all the protons and neutrons reside. The "central nucleus" and "atomic nucleus" are also frequently used to describe the same region. Finally, "core" is a more general term that can refer to the center of any object, including atoms. Regardless of the synonym used, the atom's core plays a crucial role in determining the physical and chemical properties of an atom.