Wood must be heated to the point where it what to ignite?

• A. Charrs
• B. Melts
• C. Pyrolizes
• D. Vaporizes

Answer: (C)

Ignition of wood during heating hinges on pyrolysis. As heat is applied, moisture leaves first, then the wood begins to thermally decompose. This process—pyrolysis—breaks down the wood into volatile gases and vapors. Those gases mix with the surrounding air; when their mixture reaches the right temperature, it ignites and flames appear. The solid that remains chars, forming a protective layer, but ignition itself comes from the flammable gases produced by pyrolysis, not from melting or simply turning into vapor. So the critical step is the wood undergoing pyrolysis to release combustible gases that ignite.