Question

The existence of a substance in more than one crystalline form is known as:

• A. katamorphism
• B. isomorphism
• C. metamorphism
• D. polymorphism

Answer 1

The correct option is D polymorphism

The occurrence of a given substance in more than one solid crystalline forms having different physical properties is known as polymorphism. This property when occurs in elements is known as allotropy.

Silica is known to form many polymorphs, the most important of which are; α-quartz, β-quartz, tridymite, cristobalite, moganite, coesite, and stishovite. A classical example is the pair of minerals, calcite and aragonite, both forms of calcium carbonate.

Hence,the correct option is $\text{D}$