Explanation: The processes, solution, hydration and hydrolysis, carbonation are all chemical processes and involve chemical reaction, whereas, insolation is a process of mechanical weathering.

Explanation: Pyrite is insoluble in water, whereas, rock salt, gypsum and calcite are examples of minerals that are soluble in water to some extent.

Explanation: Pure water is not a good solvent of minerals in most cases, but when the water is carbonated, its solvent action for many common minerals is enhanced. Thus, limestone is not easily soluble in pure water but carbonated water dissolves the rock effectively.

Explanation: Ions may be exchanged whereby some ions from water may enter into the crystal lattice of the mineral. This process of exchange of ions is called hydrolysis. It is a very common process of weathering of silicate minerals and is best explained with reference to weathering of mineral Orthoclase, Felspar.

Explanation: Oxidation means of either removal of electron or hydrogen or addition of oxygen but, reduction may involve removal of oxygen or addition of hydrogen or electron.

Explanation: The reaction of orthoclase with carbonic acid yields kaolinite {Al2Si2O5(OH)4 } and Pot. Carbonate and silica.

Explanation: Spheroidal weathering is a complex type of weathering observed in jointed rocks and characterized with the breaking of original rock mass into spheroidal blocks. Both mechanical and chemical weathering are believed to actively cooperate in causing spheroidal weathering. The original solid rock mass is split into small block masses by development of parallel joints.

Explanation: Weathering is affected by the factors like nature of the rock, climate, physical environment but is not affected by colour of the rock. It has no influence over its weathering.

Explanation: Among granite and sandstones exposed to atmosphere simultaneously in the same or adjoining areas having hot and humid climate, the sandstone will resist weathering to a great extent because they are made up mainly of quartz(SiO2) which is highly weathering resistant mineral.

Explanation: In the hot and humid conditions chemical weathering is predominant and not mechanical, since, there is presence of moisture.

Explanation: The resistance to weathering increases in the following order for dark coloured minerals- Olivine, Augite, Hornblende, Biotite. Hence only Biotite is most resistant. Calcite as it is very reactive among the rock forming minerals.

Explanation: The basic definition of Eluvium is “It is the end product of weathering that happens to lie over and above the parent rock”. Regolith is another term for eluvium.

Explanation: Zone B is of mixed composition, partly of soil and partly of weathered rock, the latter becoming more dominating with depth.

Explanation: Disfiguring, pitting, honeycombing and loss of surface appearance are quite common effects chemical weathering on stones used irrationally without due regard to the local environment. Scree formation happens due to mechanical weathering.

Explanation: The various process of chemical weathering operating on the rocks and minerals under different atmospheric conditions may not always end up in the formation of stable end products. Often they result in splitting of particles into smaller particles –the colloids- characterized by atoms with only partial satisfied electrical charges.