EVERYDAY SCIENCE

Detailed explanation-1: -Limestone, which is mostly calcium carbonate, reacts with carbonic acid to form caves, sinkholes and Karst topography.

Detailed explanation-2: -Caves are formed by the dissolution of limestone. Rainwater picks up carbon dioxide from the air and as it percolates through the soil, which turns into a weak acid. This slowly dissolves out the limestone along the joints, bedding planes and fractures, some of which become enlarged enough to form caves.

Detailed explanation-3: -Dissolved carbon dioxide in rainwater or in moist air forms carbonic acid, and this acid reacts with minerals in rocks. The mineral calcite, which is common in limestone, is particularly vulnerable to carbonation.

Detailed explanation-4: -Sometimes, chemical weathering dissolves large portions of limestone or other rock on the surface of the Earth to form a landscape called karst. In these areas, the surface rock is pockmarked with holes, sinkholes, and caves.

Detailed explanation-5: -There are different types of chemical weathering, the most important are: Solution-removal of rock in solution by acidic rainwater. In particular, limestone is weathered by rainwater containing dissolved CO2, (this process is sometimes called carbonation).