The appearance of colour in solid alkali metal halides is generally due to :-

1. Frankel Defect
2. Interstitial Defect
3. F-Centres
4. Schottky Defect

Concept Questions :-

Imperfections in Solids
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Difficulty Level:

A metal crystallises in two cubic crystal: FCC and BCC, whose unit cell edge lengths are 4Å and 2Å respectively. The ratio of their densities is:-

1. 1

2. 4

3. 0.25

4. 0.5

Concept Questions :-

Density/Formula/packing fraction/ Semiconductors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Ice crystallises in a hexagonal lattice having volume of the unit cell as 132 x 10-24 cm3.

If density is 0.92 g/cm3 at a given temperature, then number of  H20 molecules per unit cell is

1. 1

2. 2

3. 3

4. 4

Concept Questions :-

Density/Formula/packing fraction/ Semiconductors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

AB crystallizers in a body-centred cubic lattice with edge length a equal to 387 pm. The distance between two oppositely charged ions in the lattice is

1. 250 pm

2. 200 pm

3. 300 pm

4. 335 pm

Concept Questions :-

Introduction and Type of Crystal System
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In a face centred cubic lattice, atom A occupies the corner positions and atom B occupies the face
centre positions. If one atom of B is missing from one of the face centred points, the formula of the compound is

1.AB2

2.A2B3

3.A2B5

4.A2B

Concept Questions :-

Density/Formula/packing fraction/ Semiconductors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Percentage of free space in cubic close packed structure and in body centered packed structure are respectively:

1. 48% and 26%

2. 30% and 26%

3. 26% and 32%

4. 32% and 48%

Concept Questions :-

Density/Formula/packing fraction/ Semiconductors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Packing fraction of simple cubic crystal lattice is

1. 38%

2. 74%

3. 68%

4. 52.4%

High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In which of the following crystals alternate tetrahedral voids are occupied

1. NaCl

2. ZnS

3. CaF2

4. Na2O

Concept Questions :-

High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In a metal oxide, the oxide ions are arranged in hexagonal close packing and metal ions occupy two third of the octahedral voids. The formula of the oxide is

1. MO

2. M2O3

3. MO2

4. M2O

Concept Questions :-

Density/Formula/packing fraction/ Semiconductors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Analysis shows that an oxide ore of  nickel has formula  Ni0.98O1.00. The percentage of nickel as Ni3+ ions is nearly

1. 2

2. 96

3. 4

4. 98

Concept Questions :-

Density/Formula/packing fraction/ Semiconductors