Which stoichiometric defect does not change the density of the crystal? (A) Frenkel defect (B) Schottky defect (C) Interstitial defect (D) F-centres

Which of the following Defects is also known as dislocation defect? (A) Frenkel defect (B) Schottky defect (C) Non-stoichiometric defect (D) Simple interstitial defect

Interstitial compounds are formed when small atoms are dropped under the curved lattice of metals. Which of the following is not the characteristics property of interstitial compounds? (A) They have high melting points in to pure metals (B) They are very hard (C) They retain metallic Conductivity (D) They are chemically very reactive

Which of the following is true about the value of refractive index of quartz glass? (A) Same in all directions (B) Different in different directions (C) Cannot be measured (D) Always zero

Assertion (A): Most of the solids possess high melting point. Reason (R): They have strong intermolecular forces of attraction. [A] – Assertion & reason both statements are correct and reason is the correct explanation of assertion. [B] – Assertion & reason both are the correct statements but reason is not the correct explanation of the assertion. [C] – Assertion is correct statement and reason is incorrect statement. [D] – Assertion is incorrect statement and reason is correct statement

Assertion (A): Amorphous solids possess a long range order in the arrangement of their particles. Reason (R): The formation of amorphous solids involves very rapid cooling. [A] – Assertion & reason both statements are correct and reason is the correct explanation of assertion. [B] – Assertion & reason both are the correct statements but reason is not the correct explanation of the assertion. [C] – Assertion is correct statement and reason is incorrect statement. [D] – Assertion is incorrect statement and reason is correct statement

Assertion (A): Crystalline solids are anisotropic in nature. Reason (R): Some of their physical properties show same electrical and optical properties in different directions in the same crystal. [A] – Assertion & reason both statements are correct and reason is the correct explanation of assertion. [B] – Assertion & reason both are the correct statements but reason is not the correct explanation of the assertion. [C] – Assertion is correct statement and reason is incorrect statement. [D] – Assertion is incorrect statement and reason is correct statement

Assertion (A): The packing efficiency of simple cubic lattice is 52.4%. Reason (R): The number of atoms per unit cell is 2. [A] – Assertion & reason both statements are correct and reason is the correct explanation of assertion. [B] – Assertion & reason both are the correct statements but reason is not the correct explanation of the assertion. [C] – Assertion is correct statement and reason is incorrect statement. [D] – Assertion is incorrect statement and reason is correct statement

Assertion (A): Schottky defect arises when a non-ionic solid is heated. Reason (R): It happens because some of the lattice sites are vacant in the crystal. [A] – Assertion & reason both statements are correct and reason is the correct explanation of assertion. [B] – Assertion & reason both are the correct statements but reason is not the correct explanation of the assertion. [C] – Assertion is correct statement and reason is incorrect statement. [D] – Assertion is incorrect statement and reason is correct statement

Assertion: Diamond and graphite do not have the same crystal structure. Reason: Diamond is crystalline while graphite is amorphous. [A] – Assertion & reason both statements are correct and reason is the correct explanation of assertion. [B] – Assertion & reason both are the correct statements but reason is not the correct explanation of the assertion. [C] – Assertion is correct statement and reason is incorrect statement. [D] – Assertion is incorrect statement and reason is correct statement

Assertion: Na⁺ and Al³⁺ are isoelectronic but the magnitude of ionic radius of Al³⁺ is less than that of Na⁺ Reason: The magnitude of an effective nuclear charge on the outer shell electrons in Al³⁺ is greater than that of Na⁺. [A] – Assertion & reason both statements are correct and reason is the correct explanation of assertion. [B] – Assertion & reason both are the correct statements but reason is not the correct explanation of the assertion. [C] – Assertion is correct statement and reason is incorrect statement. [D] – Assertion is incorrect statement and reason is correct statement

Assertion: White ZnO becomes yellow upon heating. Reason: On heating ZnO loses oxygen and free electrons go into exited stated and upon returning imparts yellow radiation. [A] – Assertion & reason both statements are correct and reason is the correct explanation of assertion. [B] – Assertion & reason both are the correct statements but reason is not the correct explanation of the assertion. [C] – Assertion is correct statement and reason is incorrect statement. [D] – Assertion is incorrect statement and reason is correct statement

Assertion: The packing efficiency is maximum for the fcc structure. Reason: The coordination number is 12 in fcc structures. [A] – Assertion & reason both statements are correct and reason is the correct explanation of assertion. [B] – Assertion & reason both are the correct statements but reason is not the correct explanation of the assertion. [C] – Assertion is correct statement and reason is incorrect statement. [D] – Assertion is incorrect statement and reason is correct statement

Assertion: In caesium chloride crystal, Cs⁺ is present on the centre of cube of the unit cell. Reason: For N⁻ atoms adopting fcc arrangement, there are 2N tetrahedral voids. [A] – Assertion & reason both statements are correct and reason is the correct explanation of assertion. [B] – Assertion & reason both are the correct statements but reason is not the correct explanation of the assertion. [C] – Assertion is correct statement and reason is incorrect statement. [D] – Assertion is incorrect statement and reason is correct statement

Read the passage given below and answer the following questions: All real structures are three-dimensional structures. They can be obtained by stacking two dimensional layers one above the other while placing the second square close packed layer above the first we follow the same rule that was followed when one row was placed adjacent to the other. The second layer is placed over the first layer such that the spheres of the upper layer are exactly above there of the first layer. In his arrangement spheres of both the layers are perfectly aligned horizontally as well as vertically. A metallic element crystallise into a lattice having a ABC ABC pattern and packing of spheres leaves out voids in the lattice. 1) What type of structure is formed by this arrangement? (A) ccp (B) hcp (C) ccp/fcc (D) none of the above 2) Name the non-stoichiometric point defect responsible for colour in alkali metal halides. (A) Frenkel defect (B) Interstitial defect (C) Schottky defect (D) F-centres 3) What is the total volume of atoms in a face centred cubic unit cell of a metal? (r is atomic radius). (A) 16/3 \(πr^3\) (B) \(πr^3\) (C) 24/3 \(πr^3\) (D) 12/3 \(πr^3\) 4) Which of the following statements not true for the amorphous and crystalline solids? (A) Amorphous solids are isotropic and crystalline solids are anisotropic. (B) Amorphous solids are short range order and crystalline solids are long range order. (C) Amorphous solids melt at characteristic temperature while crystalline solids melt over a range of temperature. (D) Amorphous solids have irregular shape and crystalline solids have a geometrical shape.