If a hot piece of wood were placed in a vacuum, several interesting things would happen due to the absence of air and reduced pressure:
Evaporation: As the wood is hot, the moisture within it would start to evaporate rapidly. In a vacuum, the low pressure lowers the boiling point of water, causing it to convert directly from a solid (ice in the wood) to a gas (water vapor) without passing through the liquid state.
Combustion: Without air, the wood wouldn't burn in the conventional sense because combustion requires oxygen. However, if the wood is hot enough, it may undergo a process called pyrolysis. Pyrolysis is a chemical reaction that decomposes organic materials in the absence of oxygen, producing volatile compounds like wood gas, tar, and charcoal. These compounds may release small amounts of smoke and volatile organic compounds (VOCs).
Popping or cracking: The rapid evaporation of moisture from the wood could cause popping or cracking as the internal pressure builds and releases within the wood structure.
Expansion and contraction: The wood may experience some expansion due to the heat and then contract as it cools down.
No sound propagation: In a vacuum, there is no medium for sound to travel through, so any sound produced by the wood would not be heard.
It's important to note that conducting experiments like this should be done with caution and safety in mind. Working with hot materials can be hazardous, and vacuum systems need to be appropriately designed and handled by professionals. Without proper precautions, there could be a risk of fire, explosion, or damage to the vacuum equipment.