What are vapors defined as?

Vapors are defined as liquids that evaporate into the air, which aligns with the correct answer. In this context, a vapor occurs when a liquid substance transitions into a gaseous state due to heat or a decrease in pressure. This process allows the liquid molecules to escape into the air, creating what we perceive as vapor.

Understanding the nature of vapors is crucial in nail technology because many products used in the industry, such as nail polish, acetone, or other solvents, release vapors that can be hazardous if inhaled in high concentrations. Proper ventilation and the use of masks or other protective equipment can help mitigate these risks.

Other options refer to different physical states or conditions of matter, which are not relevant to the definition of vapors. For example, the first option describes a phase change from liquid to solid; the third option pertains to gases under pressure, and the last option involves solid particles. Each of these concepts is important, but they do not accurately describe what vapors are, which specifically involves the evaporation of liquids into the air.