Question

plastics can be divided into two general groups: thermoplastic materials and ______ materials.

Explanation:

In the field of materials science (a subfield of Natural Science, specifically related to Engineering or Chemistry in the context of plastics), plastics are commonly classified into two main groups: thermoplastic materials and thermosetting materials. Thermosetting plastics, once cured, cannot be remolded or re - melted, unlike thermoplastics which can be melted and remolded multiple times.

Answer:

thermosetting