The question involves identifying which mineral allows the maximum substitution of aluminum (Al) for silicon (Si) in its crystal structure. This kind of substitution is common in the feldspar mineral group due to the similar ionic radii and charges of Al3+ and Si4+. Understanding the chemical composition of each option can help in determining where this substitution is most prevalent.
The key to solving this question is understanding the plagioclase feldspar series, which ranges from sodium-rich albite to calcium-rich anorthite. In this series, the substitution of Al for Si increases from albite to anorthite. Therefore, the correct answer is Anorthite, as it allows for the maximum Al substitution due to its chemical composition of CaAl2Si2O8.
In summary, Anorthite allows the maximum substitution of aluminum for silicon because it has a higher aluminum-to-silicon ratio compared to the other minerals listed, which makes it the correct answer.
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Many natural disasters are caused by the volcanic activity occurring in the island arc systems.
Reason (R) : The fissure type volcanism causes the erupted lava to spread over wide areas.
In the light of the above statements, choose the most appropriate answer from the options given below :
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Gypsum has lower density than anhydrite.
Reason (R) : Hydrated minerals tend to expand many times the original volume of the anhydrous minerals.
In the light of the above statements, choose the most appropriate answer from the options given below :
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Drumlins show features opposite to those of Roches Moutonnees.
Reason (R) : The stoss side is steep and the lee side is roughened.
In the light of the above statements, choose the most appropriate answer from the options given below :
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : In a hand specimen quartz can be easily distinguished from orthoclase.
Reason (R) : Orthoclase has lower refractive index than quartz.
In the light of the above statements, choose the most appropriate answer from the options given below :
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : L waves are responsible for majority of the destructive earthquakes.
Reason (R) : They are the surface waves and develope in the immediate vicinity of the epicenter.
In the light of the above statements, choose the most appropriate answer from the options given below :
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : All continents were united together in the past.
Reason (R) : The Gangamopteris and Glossopteris flora have been found on all the southern continents.
In the light of the above statements, choose the most appropriate answer from the options given below :
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : A dip-slip fault can be a wrench fault.
Reason (R) : Along a dip fault, the net slip can be equal to strike-slip, dip-slip or oblique-slip.
In the light of the above statements, choose the most appropriate answer from the options given below :
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Chronostratigraphy is concerned with the mutual time relationship of strata.
Reason (R) : Formation, member and bed are units of chronostratigraphy.
In the light of the above statements, choose the most appropriate answer from the options given below :
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : The angle between any two faces of a crystal is termed as interfacial angle.
Reason (R) : The interfacial angles of corresponding faces of different crystals are constant if they have same chemical composition and measurements are taken at same temperature.
In the light of the above statements, choose the most appropriate answer from the options given below :
Match List - I with List - II.
| List - I Crystal System | List - II Characteristics |
|---|---|
| A. Monoclinic | I. 4 triads |
| B. Tetragonal | II. 3 diads |
| C. Orthorhombic | III. 1 tetrad |
| D. Cubic | IV. 1 diad |
Choose the correct answer from the options given below :