Total volume of atoms present in a face centred cubic unit cell of a metal is -

(r is atomic radius)

1. 20/3 $\pi$r³

2. 24/3 $\pi$r³

3. 12/3 $\pi$r³

4. 16/3 $\pi$r³

The arrangement of X^- ions around A⁺ ion in solid AX is given in the figure (not drawn to scale).
If the radius of X^-  is 250 pm, the radius of A⁺ is: 

1. 104 pm

2. 125 pm

3. 183 pm

4. 57 pm

The arrangement ABC ABC.. is referred to as.

1. octahedral close packing

2. hexagonal clase packing

3. tetrahedral close packing

4. cubic close packing

The ratio of cations to anion in a closed pack tetrahedral is:

1. 0.714

2. 0.225

3. 0.02

4. none of these

For a solid with the following structure, the co-ordination number of the point B is:

1. 3

2. 4

3. 5

4. 6

Compute the percentage void space per unit volume of unit cell in zinc fluoride structure.

1. 15.03%

2. 22.18%

3. 18.23%

4. 25.07%

8 : 8 co-ordination of CsCl is found to change into 6 : 6 co-ordination on:

1. Applying pressure.

2. Increasing temperature.

3. Both 1 and 2.

4. None of these.

The radius of Ag⁺ ion is 126 pm and that I^- ion is 216 pm. The coordination number of Ag⁺ ion is

1. 2

2. 4

3. 6

4. 8

In which of the following crystals are alternate tetrahedral voids occupied:

1. NaCl

2. ZnS

3. CaF₂

4. Na₂O

The edge length of fcc unit cell of NaCl is 508 pm. If the radius of cation is 110 pm, then the radius of the anion is : 

1. 144 pm

2. 249 pm

3. 288 pm

4. 398 pm