* Water can penetrate the rock: Permeability means the rock has interconnected pores and spaces that allow water to flow through. This allows water to reach the interior of the rock.

* Water can react with the rock: Water acts as a solvent and can dissolve minerals within the rock. This process is called chemical weathering.

* Water can freeze and expand: When water freezes, it expands. If water is trapped in the pores of a permeable rock, this expansion can put pressure on the rock and cause it to break apart. This is called frost wedging.

* Roots can penetrate the rock: Plants with deep roots can grow into the pores of permeable rocks, further breaking them apart.

In short: Permeable rocks are more susceptible to weathering because they allow water and other agents of weathering to penetrate their structure, leading to chemical and physical breakdown.