Monomer and polymer are terms associated with:

Monomer (a liquid) and polymer (a powder) are terms associated with certain nail enhancement systems, notably traditional acrylic (liquid-and-powder) enhancements, which harden as the components react. These products have strong fumes and require proper ventilation and safe handling. Cosmetologists learn the basic chemistry and safe use of enhancement systems. Recognizing monomer/polymer as enhancement-system components — and that they require ventilation and care — is part of the nail-enhancement content the exam may cover, with detailed application learned in training.