The correct order of the packing efficiency in different types of unit cells is-

1.  Fcc < Bcc < Simple cubic

2.  Fcc > Bcc > Simple cubic

3.  Fcc < Bcc > Simple cubic

4.  Bcc < Fcc > Simple cubic

The packing efficiency of the face-centered cubic unit cell is:
(assuming that the atoms are touching each other)

1. 52.40 %

2. 68.04 %

3. 74 %

4. 79.06 %

The relation between the atomic mass of unknown metal with density and the dimension of its unit cell is given by  :

(Given: All the cell edge lengths are equal)

1. \(m \ = \ \frac{\rho a^{3}N_{A}}{Z} \)
2. \(m \ = \ \rho a^{3}N_{A}Z\)
3. \(m \ = \ \frac{Z}{\rho a^{3}N_{A}}\)
4. \(m \ = \ \frac{ZN_{A}}{a^{3}\rho}\)

The most efficient packing is present in -

1. HCP and BCC

2. HCP and CCP

3. BCC and CCP

4. BCC and Simple cubic cell

Silver crystallizes in fcc lattice. If the edge length of the cell is 4.07 × 10⁻⁸ cm and density is 10.5 g cm⁻³, the atomic mass of silver is -

1. 120.31 g ${\mathrm{mol}}^{-1}$

2. 107.9 g ${\mathrm{mol}}^{-1}$

3. 207.60 g ${\mathrm{mol}}^{-1}$

4. 138.52 g ${\mathrm{mol}}^{-1}$

The fraction of total volume occupied by the atoms present in a simple cube is:

1. $\frac{\mathrm{\pi }}{6}$

2. $\frac{\mathrm{\pi }}{3\sqrt{2}}$

3. $\frac{\mathrm{\pi }}{4\sqrt{2}}$

4. $\frac{\mathrm{\pi }}{4}$

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 given metal crystallizes out with a cubic structure having an edge length of 361 pm. If there are four metal atoms in one unit cell, the radius of one atom is:

1. 40 pm
2. 127 pm
3. 80 pm
4. 108 pm

An element with a molar mass of 2.7 × 10^-2 kg mol^-1  and density  2.7 × 10³ kg m^-3  forms a unit cell with an edge length of 405 pm. The type of unit cell is-

1. Simple cubic cell.

2. Face-centered cubic cell.

3. Body-centered cubic cell.

4. None of the above.