Weathering: physical, chemical, and biological

Repeated heating and cooling in dry regions makes minerals expand and contract. In exams, link this with physical weathering.

Limestone can dissolve in water containing carbonic acid. In exams, connect karst landforms with this process.

Corners along joints expose more surface area, so weathering is stronger there. In exams, link rounded forms with fractures.

Roots exert mechanical pressure while growing and enlarge cracks. In exams, treat roots as a key example of biological weathering.

In the presence of moisture, iron minerals form rust-like compounds through oxidation. In exams, reddish-brown color is a clue for oxidation.

Physical breakage creates smaller pieces on which chemical reactions act faster. In exams, consider both processes as mutually supportive.

Water expands on freezing and exerts pressure on cracks. In exams, remember freeze-thaw cycles as the condition for frost weathering.

High temperature and moisture accelerate chemical reactions. In exams, treat climate as a major control of weathering.

After water evaporates, salts crystallize in cracks and exert pressure. In exams, link this process with dry climates.

Weathering produces regolith and mineral particles that form the base of soil formation. In exams, see soil formation as beginning with weathering.

In hydrolysis, water alters mineral structure and may form clay-like minerals. In exams, remember feldspar to clay as a key clue.

Lichens grow on surfaces and release acids that chemically decompose minerals. In exams, remember the chemical role of microorganisms.

Weathering breaks rocks in place, while erosion removes and transports them. In exams, identify in-situ action as weathering.

Cracks allow water, air, and roots to enter deeper. In exams, consider jointed rocks more vulnerable to weathering.

Less stable minerals alter faster through chemical reactions. In exams, connect mineral composition with weathering resistance.

Moisture speeds chemical reactions and organic acids enhance mineral decomposition. In exams, treat vegetation as both mechanical and chemical agent.

Regolith is loose material produced by weathering and may remain over bedrock. In exams, understand regolith as a pre-stage of soil formation.

Removal of overlying pressure or thermal stress can cause rock layers to peel. In exams, keep this as an example of physical weathering.

Lack of moisture reduces chemical reactions and temperature range increases mechanical breakage. In exams, link deserts with physical weathering.

Carbonate rocks can dissolve in water containing carbonic acid. In exams, it is important to connect karst with solution.

Human cutting exposes new surfaces to water and air. In exams, understand humans also as anthropogenic accelerators of weathering.

Few cracks reduce entry pathways and resistant minerals slow decomposition. In exams, treat both structure and composition as rate controls.

Water is the medium for most chemical weathering processes. In exams, treat moisture as a basic condition for chemical weathering.

Weathering breaks rocks into loose material on which erosion and soil formation act. In exams, treat it as an early link in geomorphic processes.

Iron and magnesium bearing minerals may alter easily under humid conditions. In exams, study mineral composition together with climate.