Close packing is maximum in the crystal which is-

(1) Simple cube                               

(2) bcc

(3) fcc                                             

(4) None

A crystal formula $A{B}_3$ has A ions at the cube corners and B ions at the edge centers. The coordination numbers of A and B are respectively 

(1) 6 and 6                                                 

(2) 2 and 6

(3) 6 and 2                                                 

(4) 8 and 8

The n of a cubic unit cell is 4. The type of cell as-

(1) Body centred                               

(2) Face centred

(3) Primitive                                     

(4) None of these

Among the following types of voids, which one is the largest void-

(1) Triangular system                             

(2) Tetragonal system

(3) Monoclinic system                             

(4) Octahedral

1. a, b                                         

2. b, c

3. a, b, c                                     

4. a, c

Copper metal has a face-centered cubic structure with the unit cell length equal to 0.361 nm. Picturing copper ions in contact along the face diagonal. The apparent radius of a copper ion is-

(A) 0.128                                         

(B) 1.42

(C) 3.22                                           

(D) 4.22

The unit cell dimensions of a cubic lattice (edges a, b, c and the angles between them, α, β, γ) are : 

1. a = b = c, $\mathrm{\alpha }= \mathrm{\beta }= \mathrm{\gamma }= 90°$

2. a = b $\ne$c, $\mathrm{\alpha }= \mathrm{\beta }= \mathrm{\gamma }= 90°$

3. a = b = c, $\mathrm{\alpha }= \mathrm{\gamma }= 90°,$ $\mathrm{\beta }\ne 90°$

4. a $\ne$b $\ne$c, $\mathrm{\alpha }= \mathrm{\beta }= 90°,$ $\mathrm{\gamma }\ne 90°$

Which is amorphous solids-

(1) Rubber                                       

(2) Plastic

(3) Glass                                         

(4) All

At room temperature, sodium crystallizes in a body-centered cubic cell with a 4.24 $\stackrel{0}{A}$. The theoretical density of sodium is- (Atomic mass of sodium=23.0 g $mo{l}^{-1}$)

(A) $2.05 g c{m}^{-3}$                                         

(B) $3.45 g c{m}^{-3}$

(C) $1.00 g c{m}^{-3}$                                         

(D) $3.55 g c{m}^{-3}$

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

(1) applying pressure

(2) increasing temperature

(3) both (a) and (b)

(4) none of these