While abrasion is a significant factor in physical weathering, it is not the most important agent of chemical weathering.

Here's why:

* Chemical weathering involves the breakdown of rocks through chemical reactions. These reactions alter the mineral composition of the rock, making it weaker and more susceptible to further weathering. Examples include:

* Oxidation: The reaction of oxygen with minerals, like iron, forming rust.

* Hydrolysis: The reaction of water with minerals, breaking them down into new compounds.

* Carbonation: The reaction of carbonic acid (formed from carbon dioxide dissolving in water) with minerals like limestone.

* Abrasion, on the other hand, is a physical weathering process. It involves the wearing away of rocks by the grinding action of other rocks, sand, or water.

Therefore, the most important agents of chemical weathering are chemical reactions, not abrasion.