Some substances are given below:
$Ag$; $CO_{2(s)}$; $SiO_2$; $ZnS$;
$SO_{2(s)}$; $AlN$; $HCl_{(s)}$; $H_2O_{(s)}$
The number of molecular solids and network solids in the above list is respectively

Match items of List-$I$ with those of List-$II$ :

List-$I$ (Property)	List-$II$ (Example)
$a$. Diamagnetism	$i$. $MnO$
$b$. Ferrimagnetism	$ii$. $O_{2}$
$c$. Paramagnetism	$iii$. $NaCl$
$d$. Antiferromagnetism	$iv$. $Fe_{3}O_{4}$

Choose the most appropriate answer from the options given below:

Given below are two statements.
Statement $I$ : $O_2, Cu^{2+}$ and $Fe^{3+}$ are weakly attracted by magnetic field and are magnetized in the same direction as magnetic field.
Statement $II$ : $NaCl$ and $H_2O$ are weakly magnetized in opposite direction to magnetic field.
In the light of the above statements,choose the most appropriate answer from the options given below:

Which of the following substances is not ferromagnetic?

The value of the heat of fusion of $NaCl$ is:

What makes a glass different from a solid such as quartz? Under what conditions could quartz be converted into glass?