What is the oxidation number of an atom in its ion state?

The oxidation number of an atom in its ion state reflects its charge. When an atom forms an ion, it either loses or gains electrons, which results in a net positive or negative charge.

For a cation, which is a positively charged ion, the oxidation number is equal to its charge. For instance, if a sodium atom loses one electron, it becomes Na⁺, and its oxidation number is +1, corresponding to the loss of that single negative charge from the neutral atom.

In the case of an anion, which is a negatively charged ion, the oxidation number would be negative, but the question specifically refers to an atom in its ion state, and the context suggests a focus on examples like cations that commonly exhibit a clear oxidation state.

Understanding this concept is crucial, as it is foundational in balancing reactions and comprehending how substances interact chemically. Thus, the oxidation number of an atom in its ion state directly reflects its charge, leading to the conclusion that +1 accurately represents a common scenario for cations.