Weathering: physical, chemical, and biological

In chelation, organic acids can bind metallic ions and weaken minerals. Remember it as a link between biological and chemical weathering.

On a stable surface, weathering products can accumulate and develop. Link time and erosion rate with mantle thickness in exams.

Physical weathering changes size and particle form, not chemical composition. Distinguish mechanical breakage from chemical change in exams.

Leaching can remove soluble components and alter the residual material. In exams, connect it with high-rainfall areas.

Sea water supplies salts and evaporation promotes crystal growth. In exams, note dry coastal micro-environments.

Slope affects material retention and water entry. In exams, write relief as a controlling factor of weathering.

Organisms mix soil and change the chemical environment. In exams, view biological activity as aiding both physical and chemical weathering.

In hydration, addition of water molecules may increase volume. Remember it as a chemical weathering process in exams.

Water and acids act on more exposed surface in smaller particles. In exams, directly link surface area with weathering rate.

Hydrolysis reduces rock strength and contributes to soil formation. Link it with humid tropical weathering in exams.

Water is very important for chemical weathering. In exams, understand aridity as a limit on chemical weathering.

The root is a biological agent, but the breakage happens by mechanical pressure. Learn to identify combined processes in exams.

Weathering prepares rock, and erosion removes it. In exams, treat weathering as the preparatory stage of landform development.

Joints divide rock into blocks, and stress can separate them. Remember joint-controlled physical weathering in exams.

Acids from humus and organisms increase mineral decomposition. In exams, write the link between organic matter and chemical weathering.

Insoluble exposed rock and high temperature range favour thermal stress. In exams, connect the process with climate and mineral type.

Water can carry chemical reactions and leaching deeper. In exams, treat rainfall as a major control of chemical weathering.

Weathering does not directly transport, but makes material removable. In exams, distinguish preparation from transport.

Solution and leaching are forms of chemical weathering and removal. In solution, minerals that can dissolve enter the water directly. In leaching, water moving through soil or broken rock carries dissolved ions downward or away from the original material. The solid rock may therefore lose some of its chemical constituents even when large pieces do not visibly break off. This is different from purely mechanical cracking.

Option A is correct because the key clue is the removal of minerals as ions dissolved in water. Thermal cracking breaks rock through heating and cooling but does not itself dissolve ions. Pressure release opens fractures by unloading, while root pressure can widen cracks through plant growth. These may be physical or biological actions, but they do not describe dissolved chemical removal. The exact ions depend on the minerals and water conditions.

Mineral stability and rock structure alter weathering rate. In exams, write rock properties along with climate.

Warmth, moisture, and time create deep chemical weathering layers. In exams, remember stable surface and long duration together.

Chemical weathering can alter mineral structure and form new minerals. In exams, use clay formation as a clear example.

Weathering is often slow, and longer duration increases its effects. In exams, connect time with climate and rock properties.

Frost cracking is physical, carbonation is chemical, and root pressure is biological weathering. In exams, match process and agent carefully.

Feldspar reacts with acidic water through hydrolysis and changes into clay minerals such as kaolin. In exams associate feldspar alteration with hydrolysis.