An alkali metal that reacts with nitrogen to form nitride is -

1. Li

2. Na

3. Cs

4. None of the above.

An alkali metals that forms only the normal oxide M₂O on heating in air is-

1. Rb

2. K

3. Li

4. Na

Alkali metals are not found in nature in their elemental state because they are : 

1. Less reactive due to low ionization energies.

2. Highly reactive due to low ionization energies.

3. Highly reactive due to low electron gain enthalpy.

4. Less reactive due to low electron gain enthalpy.

The correct order of  thermal stability of carbonates of Group 2 elements is-

1. ${\mathrm{BeCO}}_3<{\mathrm{MgCO}}_3<{\mathrm{CaCO}}_3<Sr{\mathrm{CO}}_3<{\mathrm{BaCO}}_3$

2. ${\mathrm{BeCO}}_3<{\mathrm{MgCO}}_3<{\mathrm{BaCO}}_3<{\mathrm{SrCO}}_3<{\mathrm{CaCO}}_3$

3. ${\mathrm{BaCO}}_3<{\mathrm{MgCO}}_3<{\mathrm{CaCO}}_3<Sr{\mathrm{CO}}_3<{\mathrm{BeCO}}_3$

4. ${\mathrm{BaCO}}_3<{\mathrm{CaCO}}_3<{\mathrm{MgCO}}_3<{\mathrm{SrCO}}_3<{\mathrm{BeCO}}_3$

 Superoxide is formed on heating with an excess of air by:-

1. Li, Na

2. Mg, Be

3. Na, K

4. K, Rb

In the reaction $\mathrm{M}+{\mathrm{O}}_2\to {\mathrm{MO}}_2$ (superoxide) the metal is -

1. Li                 

2. Na

3. K                 

4. Ba 

A blue coluored solution of an alkali metal in liq NH₃ is due to the presence of -

1. ${\mathrm{M}}^{-}$atoms.                                         

2. ${\mathrm{M}}^{+}$ ions .

3. Solvated anions  .                           

4. Solvated electrons.

The characteristic of alkaline earth metals is that-

1. Their general oxidation state is +1

2. They have a smaller size than alkali metals.

3. They are electronegative in nature.

4. They are strong oxidizing agents.

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

Sodium in liquid ammonia is used as :

1. Oxidizing agent .

2. Reducing agent.

3. Hydrolyzing agent.

4. Precipitating agent.