The S-block Elements

Li -> Crimson Red

Na -> Yellow

Rb -> Red violet

Cs -> Blue

VIBGYOR

Wavelength

Red violet > Crimson Red >   Yellow   >   Blue

      $\downarrow$                           $\downarrow$             $\downarrow$             $\downarrow$           

780 nm             670.8 nm     589.2 nm    455.5 nm

MgO has more lattice enthalpy than NaCl

Density of metal a very specific and depends upon many factors.

Li -> 0.53 gm/cm³

Na -> 0.97 gm/cm³

K -> 0.86 gm/cm³

Rb ->1.53 gm/cm³

Cs -> 1.90 gm/cm³

During removal of temporary hardness of water.

$\begin{array}{l}Mg{\left(HC{O}_3\right)}_2\stackrel{Boil}{\to }Mg{\left(OH\right)}_2+2C{O}_2\uparrow \\ Ca{\left(HC{O}_3\right)}_2\stackrel{Boil}{\to }CaC{O}_3+H_{2}O+C{O}_2\end{array}$

Due to higher extent of polarization by Li⁺ and Mg²⁺, LiCl and Mgcl₂ have covalent character. Therefore they are soluble in ethanol.

Due to very high value of lattice energy, LiF is having very less solubility in water.

The highest industrial consumption of hydrogen gas is in the synthesis of ammonia gas (Having manufacturing of N-based fertizers)

Ba has outer electronic configuration 6s².

CaC₂O₄ is insoluble in water.

Compound of Li are covalent so soluble in organic solvent.

Na forms strong monoacidic base.

An alkali metal oxide of formula MO₂ is super oxide which is formed by K and Rb. KO₂ has pale yellow colour and paramagnetic nature, while alkaline earth metal oxides formula MO₂ are peroxide and diamagnetic nature.

Lithium salts are extensively hydrated due to high hydration enthalpy of Li⁺

$L{i}^{+}>N{a}^{+}>K^{+}>R{b}^{+}>C{s}^{+}$ (order of polarizing power)