In heat, atoms vibrate to pass energy. In mass, molecules physically migrate from high to low concentration areas.
The mug gets hot (conduction) and steam rises (convection). Transferencia de calor y masa
numbers, or see how this applies to a specific industrial process ? In heat, atoms vibrate to pass energy
Just as there is a thermal boundary layer where temperature changes near a surface, there is a concentration boundary layer where the mixture composition changes. Real-World Example: Think of a cup of hot coffee : if you add sugar without stirring
The water evaporates into the air (diffusion/convection) and, if you add sugar without stirring, it slowly spreads through the liquid (diffusion).
This is the "fast track." When a fluid moves, it carries both thermal energy and chemical species much faster than simple diffusion or conduction alone.