Atomic structure: removing a non-neutral subatomic particle (such as an electron) from an atom changes the atom into what kind of species?

Introduction / Context:
Ion formation is central to chemistry, electrochemistry, and device physics. When an atom gains or loses electrons, its net charge changes and it behaves differently in fields, solutions, and solids.

Given Data / Assumptions:

• Start from a neutral atom with equal protons and electrons.
• Removal or addition pertains to electrons in typical chemical processes.
• The nucleus remains the same element if the proton count is unchanged.

Concept / Approach:
Charge balance governs species identity: Z protons define the element, while electron count sets the charge state. Removing an electron produces a cation; adding an electron produces an anion. Changing the proton number would change the element, but that is nuclear, not ordinary chemical, change.

Step-by-Step Solution:
Neutral atom: protons = electrons → net charge 0.Remove an electron: protons > electrons → net positive charge → cation.Add an electron: electrons > protons → net negative charge → anion.

Verification / Alternative check:
Common examples: Na → Na^+ by losing one electron; Cl → Cl^- by gaining one electron. Neither process changes the nuclear charge Z, so the element identity persists.

Why Other Options Are Wrong:
Nucleus: refers to protons and neutrons only, not the whole ionized atom.
Heavier element: element identity changes only if proton number changes.
Compound: requires multiple atoms bonded; ionization alone does not create a compound.

Common Pitfalls:
Confusing isotope (neutron change) or element transmutation (proton change) with ionization (electron change).

Final Answer:
charged ion