* Phase Change: Boiling is a phase transition where the liquid state changes to the gaseous state. This transformation happens throughout the entire body of the liquid, not just at the surface.
* Nucleation Sites: Bubbles form within the liquid, not just on the surface. These bubbles are formed at nucleation sites (imperfections, impurities) where vapor pressure is higher than the surrounding liquid.
* Heat Transfer: The heat energy required to overcome the intermolecular forces and cause the phase change is transferred throughout the liquid, not just at the surface.
In contrast, surface phenomena involve changes happening only at the surface of a material, like evaporation. Evaporation only occurs at the liquid-air interface, while boiling happens throughout the liquid.
Key takeaway: Boiling is a bulk phenomena because it involves changes happening throughout the entire volume of the liquid, driven by energy transfer and nucleation processes.
