The increasing order of reactivity among group 1 elements is 

1) Li < Na < K < Rb < Cs

2) Cs < Rb < K < Na < Li

3) Li > Na >K > Na > Cs

4) Cs > Rb > K >Na > Li

The incorrect statement about alkali metals is -

1. They have low density.

2. They have high ionization enthalpy.

3. They are highly reactive.

4. They show photoelectric effect.

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.

Sodium is less reactive than potassium because-

1. Potassium loses electron easily.

2. Sodium loses electron easily.

3. Size of sodium is larger than potassium.

4. Nuclear charge is more on potassium.

The correct diagonal relation of  Li and Mg among the following is -

1. Both form solid bicarbonates.

2. Their oxides are less soluble in water.

3.Their carbonates are ionic in nature.

4. Both form peroxides and superoxides.

Alkali and alkaline earth metals cannot be obtained by chemical reduction methods because they : 

1. Large in size.

2. Do not lose electrons.

3. Acts as a strongest reducing agent.

4. Acts as a strongest oxidising agent.

The correct statement regarding the dissolution of alkali metal in liquid ammonia is -

1. Ammoniated electron form.

2. Metal appear red in colour.

3. Metal gain electron.

4. Metal ammonia complex forms.

Be and Mg did not give flame colour because: 

1. Energy released by excited electron falls in visible region.

2. Energy released by excited electron does not fall in visible region

3. s-s transition.

4. Charge transfer.

Li₂CO₃ decomposes at a lower temperature because -

1. Lithium carbonate is not stable to heat.

2. Lithium carbonate is ionic in nature.

3. Lithium ion is unable to polarise carbonate ion.

4. Electropositive character of lithium is the highest.

The following is not a use of sodium compound 

1. Caustic soda is used in the soap industry

2. Sodium carbonate is used as a water softener

3. Sodium chloride is used for removing impurities from water

4. Quick lime is used in the manufacture of glass and cement