Discuss the general characteristics and gradation in properties of alkaline earth metals.

General properties of alkaline earth metals are as follow:

Physical Properties:


1) As we go down the group, atomic size increases due to addition of new shells.


2) These metals lose two electrons to acquire noble gas configuration. Therefore, their oxidation state is +2.


3) alkaline earth metals have large size, their ionization enthalpies are found to be fairly low. However, their first ionization enthalpies are higher than the corresponding group 1 metals.


4) As we go down the group, ionisation energy decreases, as it is easy to take out electrons now from shells.


5) Ca, Sr, and Ba impart characteristic colours to flames.


Ca – Brick red


Sr – Crimson red


Ba – Apple green


Chemical properties:


1) Alkaline earth metals react with halogens at high temperatures to form halides.


M +X2 MX2


2) All the alkaline earth metals, except Be, react with hydrogen to form hydrides.


3) They react readily with acids to form salts and liberate hydrogen gas.


M + HCl MCl2 + H2


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