Graphite and diamond are ________.

(a)

Covalent and molecular crystals

(b)

ionic and covalent crystals

(c)

both covalent crystals

(d)

both molecular crystals

In calcium fluoride, having the flurite structure the coordination number of Ca²⁺ ion and F^- Ion are ________.

(a)

4 and 2

(b)

6 and 6

(c)

8 and 4

(d)

4 and 8

The number of carbon atoms per unit cell of diamond is _______.

(a)

8

(b)

6

(c)

1

(d)

4

The composition of a sample of wurtzite is Fe_0.93 O_1.00 what % of Iron present in the form of Fe³⁺?

(a)

16.05%

(b)

15.05%

(c)

18.05%

(d)

17.05%

A solid compound XY has NaCl structure if the radius of the cation is 100pm, the radius of the anion will be ________.

(a)

\(\left( \frac { 100 }{ 0.414 } \right) \)

(b)

\(\left( \frac { 0.732 }{ 100 } \right) \)

(c)

100 x 0.414

(d)

\(\left( \frac { 0.414 }{ 100 } \right) \)

Classify the following solids
a. P₄
b. Brass
c. diamond
d. NaCl
e. Iodine

Explain briefly seven types of unit cell.

Distinguish tetrahedral and octahedral voids.

Explain Schottky defect.

Explain AAAA and ABABA and ABCABC type of three dimensional packing with the help of neat diagram.

Experiment shows that Nickel oxide has the formula Ni_0.96.O_1.00. What fraction of Nickel exists as of Ni²⁺ and Ni³+ ions?

Atoms X and Y form bcc crystalline structure. Atom X is present at the corners of the cube and Y is at the centre of the cube. What is the formula of the compound?

Write a note on Frenkel defect.