Modern 3D printers directly extrude filaments of these materials, which is much safer than the old method of shining light through a vat of toxic resin. For 10 points each:
[10e] Name this general class of materials used in 3D printers and formed from subunits called monomers.
ANSWER: polymers
[10h] Polymers like poly·lactic acid that can be extruded through a 3D printer’s nozzle must have this property, which means that they flow like liquids at high temperatures but solidify when cooled.
ANSWER: thermoplastic [prompt on plastic]
[10m] Photo·lithography instead used thermo·set polymers, which are hardened by forming these covalent bonds that connect polymer chains. Vulcanization forms these bonds in rubber.
ANSWER: cross-links [or cross-linking; prompt on link]
<Ganon Evans, Science - Chemistry> ~20545~ <Editor: Adam Silverman>