HYDROGEN AND ALKALI METALS

HYDROGEN AND ALKALI  METALS

Similarities

1.      Like Alkali metals hydrogen has only one electron in its outermost s-orbital. 

2.      Like Alkali metals, hydrogen can loose its one electron from outermost 1s¹ orbital to form H⁺ ion. 

3.      Both hydrogen and alkali metals have strong tendency to combine with halogens to form halides.

4.      Like alkali metals, Ionic compounds of hydrogen ionizes in water to give H⁺ ion.         

5.      During electrolysis of H₂O, hydrogen is obtained at cathode. Similarly during electrolysis of fused salt of alkali metals, these are obtained at cathode. 

Differences 

1.      Alkali metals are solid while hydrogen is a gas.

2.      Hydrgen needs only one electron  to complete it’s valence shell while alkali metals need seven electrons to complete  their outermost shell.

3.      Hydrogen can exist in diatomic form(H₂ ) in open atmosphere while alkali metals cannot exist in diatomic form.

4.      M⁺ ions of alkali metals are stable in aq. solution, while H⁺ ion is not stable and exist mainly as H₃O⁺ ion. 

5.      Hydrogen does not loose its electron as quickly as alkali metals

Alkali metals generally form ionic compounds while hydrogen generally forms covalent compounds.