An element has a body-centered cubic (BCC) structure with a cell edge of 288 pm. The atomic radius is:

1. $\frac{\sqrt{2}}{4}\times 288$ pm

2. $\frac{4}{\sqrt{3}}\times 288$ pm

3. $\frac{4}{\sqrt{2}}\times 288$ pm

4. $\frac{\sqrt{3}}{4}\times 288$ pm

A compounds that can show both, Frenkel as well as Schottky defects is -

1. AgBr

2. AgI

3. NaCl

4. ZnS

The formula of nickel oxide with metal deficiency defect in its crystal is $N{i}_{0.98}O$. The crystal contains ${\mathrm{Ni}}^{2+} \mathrm{and} {\mathrm{Ni}}^{3+}$ ions. The fraction of nickel existing as $N{i}^{2+}$ ions in the crystal is-

1. 0.96

2. 0.04

3. 0.50

4. 0.31

Structure of a mixed oxide is cubic close-packed (CCP). The cubic unit cell of mixed oxide is composed of oxide ions. One-fourth of the tetrahedral voids are occupied by divalent metal A and the octahedral voids are occupied by a monovalent metal B. The formula of the oxide is:

1. A₂BO₂
2. A₂B₃O₄
3. AB₂O₂
4. ABO₂

Copper has a face-centered cubic (fcc) lattice with interatomic spacing equal to 2.54Å. The value of the lattice constant for this lattice is:

1. 3.59Å

2. 2.54 Å

3. 1.27 Å

4. 5.08 Å

The cations and anions are arranged in an alternate form in:

1. Metallic crystal

2. Ionic crystal

3. Co-valent crystal

4. Semi-conductor crystal

A cube of a crystal has an A-atom placed at every corner and B-atom placed at every centre of face. The formula of the compound is:

1. AB

2. AB₃

3. A₂B₂

4. A₂B₃

Schottky defect shows:

The edge length of a face centered unit cubic cell is 508 pm. If the radius of the cation is 110 pm, the radius of the anion is:
1. 144 pm
2. 398 pm
3. 288 pm
4. 618 pm

The number of atoms per unit cell in a BCC structure is:

1. 9

2. 4

3. 2

4. 1