Property of all the alkaline earth metals that increases with their atomic number is :

(A) Solubility of their carbonates

(B) Thermal stability of their sulphates

(C) Ionisation energy

(D) Electronegativity

Which of the following acts as an oxidizing as well as a reducing agent?

(1) ${\mathrm{Na}}_2\mathrm{O}$                                     

(2) ${\mathrm{NaO}}_3$

(3) $\mathrm{NaNO}$                                     

(4) ${\mathrm{NaNO}}_2$

A metal [X] heating on nitrogen gas gives [Y]. [Y] on treatment with ${\mathrm{H}}_2\mathrm{O}$ gives a colourless gas which when passed through ${\mathrm{CuSO}}_4$ solution gives a blue colour. [Y] is-

1. $\mathrm{Mg}{\left({\mathrm{NO}}_3\right)}_2$                                     

2. ${\mathrm{Mg}}_3{\mathrm{N}}_2$

3. ${\mathrm{NaN}}_3$                                             

4. $\mathrm{MgO}$

The correct relation about the density of Na and K is 

1. Na > K                                                     

2. Na = K

3. K > Na                                                     

4. Li > K

In $K^{+}{F}^{-}$ ionic radius of $F^{-}$ is more while atomic radius of $K^{+}$ is –

(1) Less than $F^{-}$

(2) More than $F^{-}$

(3) Equal to $F^{-}$

(4) None of these

Lattice energy is lowest for –

1. LiF                                                       

2. NaCl

3. KBr                                                       

4. CsI

Which of the following halides has the highest melting point-

(A) NaCl                                           

(B) KCl

(C) NaBr                                           

(D) NaF

Alkaline earth metals form hydrated crystalline solids such as $MgC{l}_2.6H_{2}O,<mspace\; width="1em"></mspace>CaC{l}_2.6H_{2}O$. This is due to-

(1) Smaller ionic size

(2) Increased charge on ions

(3) Higher hydration enthalpies

(4) High oxidation potential

Magnesium can be prepared by heating-

(1) $MgC{l}_2$ with CaO at 1775 K

(2) $MgC{l}_2$ with $Ca{C}_2$ at 1775 K

(3) $MgC{l}_2$ with $Ca{\left(OH\right)}_2$ under pressure

(4) MgO with $Ca{C}_2$ at ordinary temperature

A chloride dissolves appreciably in cold water. When placed in a platinum wire in Bunsen flame no distinctive colour is noticed. Which cation could be present –

(1) $B{e}^{2+}$                                         

(2) $B{a}^{2+}$

(3) $P{b}^{2+}$                                         

(4) $C{a}^{2+}$