Characteristics of Alkali Metals:

1.    Each member of group IA or group 1 has ns1 arrangement of electrons where n represents for the outermost shell i.e., all these members possess only on electron in their outermost shell followed with (n – 1)s2p6 or (n – 1)s2 (i.e., Li).

    Lithium           or    ₃Li         :    1S², 2s^₁ or [He] 2s¹

    Sodium          or    ₁₁Na     :    1s², 2s²2p⁶, 3s¹ or [Ne] 3s¹

    Potassium    or    ₁₉K        :    1s², 2s²2p⁶, 3s²2p⁶, 4s¹ or [Ar] 4s¹

    Rubidium      or    ₃₇Rb     :    1s², 2s²2p⁶, 3s²3p⁶d¹⁰, 4s²4p⁶d¹⁰, 5s²5p⁶, 6s¹
                                                        or [Xe] 6s1

    Caesium       or    ₅₅Cs     :    1s², 2s²2p⁶, 3s²3p⁶3d¹⁰, 4s²4p⁶d¹⁰, 5s²5p⁶, 6s¹
                                                        or [Xe] 6s1

    Francium        or    ₈₇Fr     :    1s², 2s²2p⁶, 3s²3p⁶3d¹⁰, 4s²4p⁶4f¹⁴, 5s²5p⁶5d¹⁰, 6s²6p⁶, 7s¹

                                                         or [Rn] 7s¹


2.    Because of similarity in electronic configuration, they exhibit similar properties. A regular gradation in their properties with increase in at. no. is observed due to increasing size of atoms/ions and the low binding energy of valency electrons.

3.    Of all the alkali metals, only sodium and potassium are found in abundance in nature. Francium occurs only in minute quantities as a radioactive decay product.
    Physical Nature

Some important ores of alkali metals are as follows:
       
Lithium         :    Tiphylite, Petalite, Lepidolite, Spodumene, [LiAl(SiO3)3],     Amblygonite [Li(AIF)PO4]

Sodium        :    Chile salt petre (NaNO3), Rock slt or Sodium chloride (NaCI), Sodium sulphate (Na2SO4), Borax (Na2B4O7.10H2O),

                          Glauber salt (Na2SO4.10H2O), Natron (Na2CO3.HO), Soda Felspar (NaAISi3O8), Cryolite (Na3AI6) and Trona 

                          (Na2CO3.2NaHCO3.3H2O).      

  
Potassium    :    Sylvine (KCI), carnallite (KCI.MgCI2.6H2O), Felspur (K2O.AI2O3.6SiO2), Polyhalite (K2SO4.MgSO4.CaSO4.6H2O), Indian salt 

                             peter (KNO3) and Kainite (KCI.MgSO4.MgCI2.3H2O).  

                    
Rubidium     :    Lepidolite, triphylite Lithium ores contains 0.7 to 3% Rb2O.

Caesium     :    Lepidolite, Pollucite contains 0.2 to 7% Cs2O

characteristics:

1. they are metallic in nature and are electropositive in nature.

2.they form ionic compounds(Li is sometimes an exception)

3.they always exhibit +ve oxidation state.

ores:

1.dolomite

2.carnallite

3.rock salt

priyanka