In context with beryllium, which one of the following statements is incorrect?

1.  It is rendered passive by nitric acid

2.  It forms ${\mathrm{Be}}_2\mathrm{C}$

3. Its salts rarely hydrolyse

4.  Its hydride is electron-deficient and polymeric

Which of the following oxides is most acidic in nature?

1. MgO

2. BeO

3. BaO

3. CaO

On heating which of the following releases CO₂ most easily?

1. ${\mathrm{K}}_2{\mathrm{CO}}_3$

2. ${\mathrm{Na}}_2{\mathrm{CO}}_3$

3. ${\mathrm{MgCO}}_3$

4. ${\mathrm{CaCO}}_3$

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

1. Rb

2. K

3. Li

4. Na

The ease of adsorption of the hydrated alkali metal ions on ion-exchange resins follows the order

1. ${\mathrm{Li}}^{+}<{\mathrm{K}}^{+}<{\mathrm{Na}}^{+}<{\mathrm{Rb}}^{+}$

2. ${\mathrm{Rb}}^{+}<{\mathrm{K}}^{+}<{\mathrm{Na}}^{+}<{\mathrm{Li}}^{+}$

3. ${\mathrm{K}}^{+}<{\mathrm{Na}}^{+}<{\mathrm{Rb}}^{+}<{\mathrm{Li}}^{+}$

4. ${\mathrm{Na}}^{+}<{\mathrm{Li}}^{+}<{\mathrm{K}}^{+}<{\mathrm{Rb}}^{+}$

Which of the following compounds has the lowest melting point?

1.  ${\mathrm{CaBr}}_2$

2.  ${\mathrm{Cal}}_2$

3.  ${\mathrm{CaF}}_2$

4.  ${\mathrm{CaCl}}_2$

Which of the following alkaline earth metal sulphates has hydration enthalpy higher than the lattice enthalpy?

1. ${\mathrm{CaSO}}_4$

2. Mg${\mathrm{SO}}_4$

3. ${\mathrm{BaSO}}_4$

4. ${\mathrm{SrSO}}_4$