What reaction is involved in the hardening of nail polish?

The hardening of nail polish primarily involves the process of polymerization, which is a chemical reaction where small molecules called monomers join together to form a more complex structure known as a polymer. In the case of nail polish, this process is essential as it transforms the liquid formula into a solid film that adheres to the nail.

While evaporation plays a role in the drying of traditional nail polish by allowing solvents to escape, it is not the primary reaction responsible for the hardening. The actual solidification and durability of the polish come from the polymer chains that form during polymerization.

Curing may refer to various processes depending on the product, but in the context of nail polish, it primarily relates to specific formulations like gel polish, which require a UV or LED light to initiate polymerization. Oxidation may occur in some chemical interactions related to nail products but isn't the main process for hardening nail polish.

In summary, polymerization is the correct reaction involved in the hardening of nail polish, as it directly contributes to forming the solid structure that gives the polish its strength and longevity on the nails.