According to the periodic table, which statement
correctly describes the change from a neutral atom of
an element to its ion?

Sodium atom lose one valance electron and form cation with charge of +1.

Chlorine atom gain one electron and form the anion with charge of -1.

Explanation:

Neutral atom loses are gains the the electrons and form ions.

There are two types of ions. Cation and anion

Cation:

When a neutral atom lose electron it form cation. The charge gained by atom is depending upon how many electrons are lost by atom. For example,

X → X⁺ + e⁻

In case of sodium:

Na  → Na⁺ + e⁻

Anion:

When a neutral atom gain electron it form anion. The charge gained by atom is depending upon how many electrons are gained by atom. For example,

X + e⁻  →  X⁻

In case of chlorine:

Cl + e⁻  →  Cl⁻

c) should be the answer.