Which s not a particle within an atom a neutron an electron an ion a proton?

An Ion

Explanation:

An ion is a charged particle. When an atom or molecule lose or gain electrons, ions are formed. Positively charged ions are formed when some atom loses its electrons. The other atom that has gained the electrons forms negatively charged ions. Ions are not present inside the atom. Rather, ions are charged atoms.

Example: Na+, K+, Cl-

answer; i believe that the correct answer is(d) nondisjunction during meiosis;