Which statement defines an oxidizer?

• A. A substance that consumes oxygen.
• B. A substance that provides oxygen to support combustion.
• C. A substance that reduces ignition temperature.
• D. A substance that acts as a solvent.

Answer: (B)

An oxidizer is an oxidizing agent that supplies oxygen to support the oxidation of a fuel. In combustion, you need an oxidant to accept electrons from the fuel and release oxygen-containing species that keep the reaction going. Substances that release oxygen to support burning are called oxidizers, which is why this statement is the best description.

Note how the other ideas aren’t defining features: something that consumes oxygen would hinder combustion rather than enable it; reducing ignition temperature isn’t a universal property of oxidizers, though some additives can have that effect; and acting as a solvent isn’t relevant to the role of oxidizers in promoting oxidation.