Final answer:
Portable extinguishers use three mechanisms to expel their contents: expanding gas, inert gas displacement, and chemical reaction.
Step-by-step explanation:
- Expanding gas: Portable extinguishers use compressed air that expands into the lower-pressure air of the room, causing a greater dispersal of the extinguishing agent.
- Inert gas displacement: Some extinguishers use inert gases like carbon dioxide to displace the oxygen, smothering the fire.
- Chemical reaction: Certain extinguishers contain chemicals that undergo a chemical reaction when released, creating substances that can effectively extinguish fires.