In an f.c.c. unit cell. atoms are numbered as shown below. The atoms not touching each other are (Atom numbered 3 is face centre of front face).

1. 3&4

2. 1&3

3. 1&2

4. 2&4

Which is covalent solid?

1. Silicate

2. Diamond

3. Graphite 

4. All of these

The mass of a unit cell of CsCl corresponds to:-
1. 8Cs⁺ and Cl^-
2. 1Cs⁺ and 6Cl^-
3. 1Cs⁺ and 1Cl^-
4. 4Cs⁺ and Cl^-

Graphite in an example of-

1. Ionic solid

2. Covalent solid

3. Molecular Solids

4. Metallic crystal

The intermetallic compound LiAg has a cubic crystalline structure in which each Li atom has 8 nearest neighbour silver atoms and vice-versa. What is the type of unit cell?

1. Body centred cubic

2. Face centred cubic

3. Simple cubic for either Li atoms alone or Ag atoms alone

4. None of the above

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

TiO₂ is a well-known example of:

1. Triclinic system.

2. Tetragonal system.

3. Monoclinic system.

4. None of the above.

The elements of symmetry in a crystal are:-

1. Plane of symmetry

2. Axis of symmetry

3. Centre of symmetry

4. All of the above

A solid has a structure in which W atoms are located at the corners of a cubic lattice. Oxygen atom at the centre of the edges and Na atom at centre of the cube. The formula of the compound is 

1. NaWO₂

2. NaWO₃

3. Na₂WO₃

4. NaWO₄

AB crystallizes in a body-centred cubic lattice with edge length a equal to 387 pm. The distance between two oppositely charged ions in the lattice will be : 

1. 250 pm

2. 200 pm

3. 300 pm

4. 335 pm