Acidic water can react with limestone to break the rock down and form caves in the Earth's surface. This is an example of , which happens over time.

Filling in the blank, this is an example of chemical weathering which happens to rocks overtime.

Explanation:

Chemical weathering occurs when rocks are disintegrated by chemicals.

Rain water becomes acid rain when it reacts with carbon dioxide in the atmosphere (to form carbonic acid, HCO3).

When acidic rainwater falls and stays on rocks, chemical reactions take place with the minerals present in the rock, causing the rock to weather.

Areas with immense carbon dioxide and sulphur dioxide pollution increases rain water acidity, which in turn causes moisture in the atmosphere to dissolve these gases and produce acid rain.

Chemical weathering; to exposed rock surfaces.

Explanation:

Weathering involves the process in which rocks are being broken down that is to say the wearing and dissolution of exposed rock surfaces. And one of the agents of weathering is acid. There are different types of weathering but the one that concerns this question is known as chemical weathering.

Chemical weathering occurs when Acidic gas such as Carbondioxide combines with water vapour in the atmosphere to produce acidic rain which is known as the carbonic acid. When this acidic rain react with limestone it can form caves.