What happens when a UV gel enhancement is applied?

When UV gel enhancement is applied, it undergoes a curing process which causes it to harden. This hardening occurs because the UV light initiates a chemical reaction in the gel formula, causing it to polymerize. As the gel is exposed to the UV light, the molecules link together, transforming the gel from a liquid state into a solid state. This is essential in nail technology as it ensures the durability and integrity of the enhancement, allowing it to withstand wear and tear while providing a foundation for nail art or a polished finish.

As for the other options, softening or evaporation do not accurately describe the effect of UV light on gel; rather, those processes would not be beneficial and are not part of the intended functioning of the enhancement. The sticky residue that may remain after curing is often a surface layer that can be wiped off with a cleanser, but it does not reflect the core action of the gel hardening under UV light.