I. Mg(s)

II. TiO(s)

III. I₂(s)

IV. H₂O(s)

The insulator among the given examples is -

1. Only I

2. Only II

3. III and IV

4. II, III, and IV

Which of the following is not the characteristic of ionic solids?
 

Graphite is a good conductor of electricity due to the presence of ......... .

(1) Lone pair of electrons.

(2) Free valence electrons.

(3) Cations.

(4) Anions.

Which of the following oxides behaves as a conductor or insulator depending upon temperature?

1.  TiO

2.  SiO₂

3.  TiO₃

4.  MgO

Which of the following oxides shows electrical properties like metals?

1.  SiO₂

2.  MgO

3.  SO₂ (s)

4.  CrO₂

The lattice site in a pure crystal cannot be occupied by ......... .

1.  Molecule

2.  Ion

3.  Electron

4.  Atom

Graphite cannot be classified as ...........

1.  Conducting solid.

2.  Network solid.

3.  Covalent solid.

4.  Ionic solid.

Cations are present in the interstitial sites in ............ .

1.  Frenkel defect.

2.  Schottky defect.

3.  Vacancy defect.

4.  Metal deficiency defect.

Schottky defect is observed in crystals when:

Chargewise p-type semiconductor is -

1. Positive.

2. Neutral.

3. Negative.

4. Depends on the concentration of p impurity.