A crystal formula AB₃ has A ions at the cube corners and B ions at the edge centres. The coordination number of A and B respectively

1. 6 and 6

2. 2 and 6

3. 6 and 2 

4. 8 and 8

An alloy of copper, silver and gold is found  to ave copper constituting the ccp lattice. If silver atoms occupy the edge centres and gold is present at body centre, the alloy has a formula - 

1. Cu₄Ag₂Au

2. Cu₄Ag₄Au

3. Cu₄Ag₃Au

4. CuAgAu

Choose the correct matching sequence from the possibilities given

How many octahedral and tetrahedral holes are present per unit cell in a face centred cubic arrangement of atoms?

1. 8,4

2. 1,2

3. 4,8

4. 2 ,1

Frenkel defect is noticed in:

1. AgBr

2. ZnS

3. Agl

4. All of the above

The most efficient packing of similar spheres is obtained in 

1. The simple cubic system and the body centered cubic system

2. The simple cubic system and the hexagonal close packed system

3. The face centered cubic system and the hexagonal close packed system

4. The body centered cubic system and the face centered cubic system

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

The arrangement ABC ABC.. is referred to as.

1. octahedral close packing

2. hexagonal clase packing

3. tetrahedral close packing

4. cubic close packing

Select the correct statement (s)-

(a) The C.N. of cation occupying a tetrahedral hole is 4.

(b) The C.N. of cation occupying a octahedral hole is 6.

(c) In schottky defects, density of the lattice decreases,

1. a,b

2. b,c

3. a,b,c

4. a,c

Graphite in an example of-

1. Ionic solid

2. Covalent solid

3. Molecular Solids

4. Metallic crystal