Key concepts
Evaporation occurs at a liquid surface at any temperature. Faster molecules are more likely to escape. Boiling occurs throughout a liquid when its vapor pressure matches outside pressure.
This lab uses a simplified probability model. Particle sizes, speeds, and counts are visually scaled and are not literal molecular measurements.
Real-world connections
Sweating cools skin, wet clothes dry by evaporation, pressure cookers raise water’s boiling point, and vacuum processing removes solvents at lower temperatures.