Step 1: Understand that BET theory is related to how gases or liquids stick to surfaces.
Step 2: Know that 'adsorption' means the process of molecules attaching to a surface.
Step 3: Recognize that BET theory is an extension of the Langmuir model, which only considers one layer of molecules.
Step 4: Learn that BET theory allows for multiple layers of molecules to be adsorbed on a surface, not just one.
Step 5: Conclude that BET theory is important for understanding how materials with pores (like activated carbon) can hold more than one layer of gas or liquid.
