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.

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 correct statement(s) about the structure of BeCl₂ is -
a. BeCl₂ (solid)- exists as polymer.
b. BeCl₂ (vapour)- exists as chlorobridged dimer.
c. BeCl2 has bent structure in the vapour phase.
1. a
2. a & b
3. b
4. b & c

BaO is soluble but BaSO₄ is insoluble in water because : 

1. BaSO₄ is unstable.

2. BaO is unstable.

3. Lattice energy of BaO is higher.

4. Ba²⁺ is a small cation and O^2- is a large anion.

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 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.

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.

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

1. Rb

2. K

3. Li

4. Na