Page 2 - Microsoft Word - Module-3

TRENDS IN PHYSICAL PROPERTIES:

 Alkaline earth metals are silvery white, lustrous and

relatively soft but harder than the alkali metals.

 The m.p and b.p of alkaline earth metals are higher

than those of corresponding alkali metals due to

smaller size.

 Because of the low I.E they are strongly electro

positive in nature and the electro positive character

increases down the group.

 Ca, Sr and Ba impart characteristic brick red, crimson

and apple green colors respectively to the flame.

 Be and Mg do not impart any color to the flame

because their electrons are too strongly bound to

get excited by flame.

TRENDS IN CHEMICAL PROPERTIES

The alkaline earth metals are less reactive than alkali

metals and the reactivity of these elements increases

down the group.

Reactivity towards air and water:

 Be and Mg are kinetically inert to oxygen and water

because of the formation of an oxide film on their

surface.