Ion properties reveal atomic structure of Q

Steps:

• Positive ion lost electrons, so neutral atom has more than 10 electrons; thus, atomic number Z (protons) > 10.
• Ion has 14 neutrons, unchanged from neutral atom.
• Mass number A = Z + neutrons = Z + 14.
• Since Z > 10, A > 24.

Why D is correct:

• Mass number equals protons plus neutrons; with Z > 10 and 14 neutrons, A exceeds 24 by definition.

Why the others are wrong:

• A: Q forms positive ions, indicating a metal, not non-metal; electron shells exceed two for Z > 10.
• B: Statement is incomplete; while likely a metal, "only" lacks specificity without full periodic table context.
• C: Atomic number equals neutral electrons (or protons), which exceeds 10, not equal to ion's electrons.

Final answer: D