What type of weathering involves the chemical alteration of rock?

Chemical weathering is the process that involves the chemical alteration of rocks and minerals. During chemical weathering, the minerals within the rock undergo changes due to reactions with water, acids, and other chemical agents present in the environment. This can lead to the dissolution of minerals, the formation of new minerals, or the alteration of existing minerals.

For example, when carbon dioxide in the atmosphere combines with rainwater, it forms carbonic acid, which can react with minerals like calcite in limestone, leading to its dissolution. This type of weathering is essential as it contributes to soil formation and affects the overall landscape by changing the mineral composition of rocks over time.

Mechanical, physical, and biological weathering pertain to different processes, such as physical breakdown of rocks without changing their chemical composition or the influence of living organisms on rock disintegration. These do not involve chemical alterations, which makes chemical weathering the correct answer in this context.