Which of the following biologically important ions is also a constituent of the sodium pump?

1. Ca²⁺
2. Mg²⁺
3. K⁺
4. Fe²⁺

Solubility of alkaline earth metal sulphates in water decreases in the sequence:

1. Mg > Ca > Sr >Ba
2. Ca > Sr > Ba > Mg
3. Sr > Ca > Mg > Ba
4. Ba > Mg > Sr > Ca

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

 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.  ${\mathrm{CaOCl}}_2$

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

Which one of the following compounds is a peroxide?

1. $K{O}_2$

2. $Ba{O}_2$

3. $Mn{O}_2$

4. $N{O}_2$

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. $SrS{O}_4$