When burned, thermoplastics do not produce which of the following?

Thermoplastics are materials that, when heated, become soft and moldable, and upon cooling, solidify again. When burned, they do undergo combustion, which typically produces soot, smoke, and heat. Soot is formed as incomplete combustion occurs, smoke consists of a mixture of gases and fine particles that result from the burning process, and heat is a byproduct of combustion.

Char, on the other hand, is a residue that forms when carbon-based materials are burned at high temperatures and can also be produced by the pyrolysis of certain materials. While thermoplastics do not char to the same extent as some other materials, they can produce less char compared to materials like wood or certain other polymers. Therefore, the production of char is not characteristic of thermoplastic combustion when comparing it to other combustion products like soot, smoke, and heat.

In summary, when thermoplastics burn, they produce soot, smoke, and heat, making the lack of char in their combustion the distinguishing factor for this question.