The alkali metals form salt-like hydrides by direct synthesis at elevated temperatures. The thermal stability of these hydrides decreases in which of the following orders?

1. CsH > RbH > KH > NaH > LiH

2. KH > NaH > LiH > CsH > RbH

3. NaH > LiH > KH > RbH > CsH

4. LiH > NaH > KH > RbH > CsH

The correct order of increasing thermal stability of K₂CO₃, MgCO₃, CaCO₃, and BeCO₃ is:

1. $BeC{O}_3<MgC{O}_3<K_{2}C{O}_3<CaC{O}_3$

2. $BeC{O}_3<MgC{O}_3<CaC{O}_3<K_{2}C{O}_3$

3. $MgC{O}_3<BeC{O}_3<CaC{O}_3<K_{2}C{O}_3$

4. $K_{2}C{O}_3<MgC{O}_3<CaC{O}_3<BeC{O}_3$

In which of the following the hydration energy is higher than the lattice energy?

1. $BaS{O}_4$

2. $MgS{O}_4$

3. $CaS{O}_4$

4. $SrS{O}_4$

The correct order of the mobility of the alkali metal ions in aqueous solution is:

1. $L{i}^{+}>N{a}^{+}>K^{+}>R{b}^{+}$

2. $N{a}^{+}>K^{+}>R{b}^{+}>L{i}^{+}$

3. $K^{+}>R{b}^{+}>N{a}^{+}>L{i}^{+}$

4. $R{b}^{+}>K^{+}>N{a}^{+}>L{i}^{+}$

Which of the following is an amphoteric hydroxide?

1.  $\mathrm{Be}{\left(\mathrm{OH}\right)}_2$

2.  $\mathrm{Sr}{\left(\mathrm{OH}\right)}_2$

3.  $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$

4.  $\mathrm{Mg}{\left(\mathrm{OH}\right)}_2$

Which one of the following compounds is a peroxide?

1. $K{O}_2$

2. $Ba{O}_2$

3. $Mn{O}_2$

4. $N{O}_2$

Among the given options, what is the property of the alkaline earth metals that increases with their atomic number?
1. Solubility of their hydroxides in water
2. Solubility of their sulphates in water
3. Ionization energy
4. Electro-negativity

 An active ingredient in bleaching powder that aids in the bleaching action is:

1.  $\mathrm{Ca}{\left(\mathrm{OCl}\right)}_2$

2.  ${\mathrm{CaO}}_2\mathrm{Cl}$

3.  ${\mathrm{CaCl}}_2$

4.  ${\mathrm{CaOCl}}_2$

Which one of the following alkali metals forms only the normal oxide M₂O on heating in air?

1. Rb

2. K

3. Li

4. Na