What term describes the charge an atom appears to have in a neutral molecule or modified polyatomic ion?

• A. Disproportionation
• B. Oxidation number
• C. Half cell
• D. Electrolyte

Answer: (B)

Oxidation numbers are the charges assigned to atoms in molecules or ions to keep track of electrons in redox processes. They’re a bookkeeping tool, not the actual physical charge on the atom, used to determine how electrons are transferred during reactions. In a neutral molecule, the sum of all oxidation numbers is zero; in a polyatomic ion, the sum equals the ion’s overall charge. The rules (like fluorine always -1, oxygen usually -2, hydrogen usually +1) help you assign these numbers consistently based on electronegativity and bonding. This concept lets you see at a glance which atoms are oxidized or reduced in a reaction. The other terms relate to different ideas: disproportionation is a redox reaction where a species is both oxidized and reduced to form two species, a half cell is a component of an electrochemical cell, and an electrolyte is a substance that conducts ions.