What does an oxidizer do in relation to combustion?

• A. Initiates or promotes combustion by releasing oxygen or other gases
• B. Inhibits combustion
• C. Absorbs heat to prevent ignition
• D. Forms water and carbon dioxide

Answer: (A)

An oxidizer’s role in combustion is to provide the oxygen or other oxidizing species that fuel needs to burn. In a fire, the fuel reacts with an oxidizer to release energy, and oxidizers can do this by supplying oxygen gas or by releasing other oxygen-containing molecules when they decompose. Without an oxidizer, the fuel may not ignite or will burn much more slowly.

That’s why the best choice describes the oxidizer as initiating or promoting combustion by releasing oxygen or other gases. It isn’t about inhibiting combustion, which would calm or extinguish a fire; it isn’t about absorbing heat to prevent ignition, which would cool things down; and it isn’t about forming water and carbon dioxide, which are products of the combustion reaction rather than the role of the oxidizer itself.