Which of the following conditions favours the existence of a substance in the solid state?

1.  High temperature

2.  Low temperature

3.  High thermal energy

4.  Weak cohesive forces

The incorrect statement among the following regarding crystalline solid is -

An example of amorphous solid among the following is -

1. Graphite (C)

2. Quartz glass (SiO₂)

3. Chrome alum

4. Silicon carbide (SiC)

Which of the following arrangements shows the schematic alignment of magnetic moments of antiferromagnetic substances? 

1. $\overline{)\uparrow }$ $\overline{)\uparrow }$ $\overline{)\uparrow }$ $\overline{)\uparrow }$ $\overline{)\uparrow }$ $\overline{)\uparrow }$

2. $\overline{)\downarrow }$ $\overline{)\downarrow }$ $\overline{)\downarrow }$ $\overline{)\downarrow }$ $\overline{)\downarrow }$ $\overline{)\downarrow }$

3. $\overline{)\uparrow }$ $\overline{)\uparrow }$ $\overline{)\downarrow }$ $\overline{)\uparrow }$ $\overline{)\uparrow }$ $\overline{)\downarrow }$

4. $\overline{)\uparrow }$ $\overline{)\downarrow }$ $\overline{)\uparrow }$ $\overline{)\downarrow }$ $\overline{)\uparrow }$ $\overline{)\downarrow }$

Which of the following is true about the value of refractive index of quartz glass?

1. Same in all directions

2. Different in different directions

3. Cannot be measured

4. Always zero

Incorrect statement among the following about amorphous solids is -

The sharp melting point of crystalline solids is due to......... .

Iodine molecules are held in the crystals lattice by ........ .

1.  London forces.

2.  Dipole-dipole interactions.

3.  Covalent bonds.

4.  Coulombic forces.

Network solid, among the following, is :

1. SO₂(solid)

2. I₂

3. Diamond

4. H₂O(ice)

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