Lithium has a bcc structure. Its density is 530 kg m^-3 and its atomic mass is 6.94 gmol^-1.

The edge length of a unit cell of lithium metal is -

(N_A=6.02 x10²³ mol^-1)

1. 352 pm

2. 527 pm

3. 264 pm

4. 154 pm

 

The ionic radii of A⁺ and B^- ions are 0.98 x 10^-10 m and 1.81 x10^-10 m.  The coordination

number of each ion in AB is.

1. 4

2. 8

3. 2

4. 6

The correct statement regarding defects in the crystalline solid is

1. Schottky defects have no effect on the density of crystalline solids

2. Frenkel defects decreases the density of crystalline solids

3. Frenkel defcct is a dislocation defect

4. Frenkel defect is found in halides of alkaline metals

The vacant space in bcc lattice cell is ;

1. 26%

2. 48%

3. 23%

4. 32%

if a is the length of the side of a cube, the distance between the body centered atom and

one corner atom in the cube will be :-

1. $\frac{2}{\sqrt{3}}a$

2. $\frac{4}{\sqrt{3}}a$

3. $\frac{\sqrt{3}}{4}a$

4. $\frac{\sqrt{3}}{2}a$

Copper crystallises in a face-centred cubic lattice with a unit cell length of 361 pm. What

is the radius of copper atom in pm?

1. 128

2. 157

3. 181

4. 108

Lithium metal crystallises in a body centred cubic crystal. If the length of the side of the

unit cell of lithium is 351 pm, the atomic radius of the lithium will be

1. 240.8 pm

2. 151.8 pm

3. 75.5 pm

4. 300.5 pm

The incorrect statement among the following is:

If 'a' stands for the edge length of the cubic systems: simple cubic, body centered cubic and face centered cubic, then the ratio of radii of the spheres in these systems will be respectively,

$\left(\mathrm{a}\right) \frac{1}{2}\mathrm{a}: \frac{\sqrt{3}}{4}\mathrm{a}:\frac{1}{2\sqrt{2}}\mathrm{a} \left(\mathrm{b}\right) \frac{1}{2}\mathrm{a}:\sqrt{3}\mathrm{a}:\frac{1}{\sqrt{2}}\mathrm{a}$
$\left(\mathrm{c}\right) \frac{1}{2}\mathrm{a}:\frac{\sqrt{3}}{2}\mathrm{a}:\frac{\sqrt{2}}{2}\mathrm{a} \left(\mathrm{d}\right) 1\mathrm{a}:\sqrt{3}\mathrm{a}:\sqrt{2}\mathrm{a}$

Percentage of free space in a body centered cubic unit cell is

(1) 30%                       

(2) 32%

(3) 34%                       

(4) 28%