What are the common physical and chemical features of alkali metals?

Explanation

Physical properties:
(1) All the alkali metals are soft metals with low m.pts and b.pts.
In each period the alkali metals have large atomic sizes.
(3) All the alkali metals exhibit only one oxidation state + 1.
(4) All the alkali metals exhibit flame colours.
(5) Alkali metals have low IP and have tendency to lose electrons. So they act as strong reducing agents.
Chemical Properties:
(1) All the alkali metals react with oxygen in air forming oxides.
(ii) All the alkali metals reacts with water liberating hydrogen. The reactivity of alkali metals increases down the group.
(iii) All the alkali metals reacts with hydrogen forming ionic hydrides.
(4) All the alkali metals react with halogen forming similar halides of the type Mx.
(5) The oxides and hydroxides of the alkali metals are strongly alkaline.
(6) All the alkali metals dissolve in ammonia forming blue coloured solutions due to the presence of ammoniated electrons. These solutions are good reducing agents, good conductors of electricity and paramagnetic.