S-BLOCK ELEMENTS

S-BLOCK ELEMENTS. RIYA GUPTA 11-A1.

. They form hydroxides on reaction with water which are strongly alkaline in nature. The alkali metals show regular trends in their physical and chemical properties with the increasing atomic number ..

TRENDS. ELECTRONIC CONFIGURATION: all alkali metals have one valence electron. The loosely held s-electron in the outermost valence shell of these elements makes them the most electropositive metals..

PHYSICAL PROPERTIES. All alkali metals are silver white , soft and light metals. Because of the larger size , these elements have low density which increase down the group from Li to Cs..

CHEMICAL PROPERTIES. REACTIVITY WITH AIR: The alkali metals tarnish in dry air due to the formation of their oxides which in turn react with moisture to form hydroxides. They burn vigorously..

HALOGENS : The alkali metals readily react vigorously with halogens to form ionic halides. Lithium halides are somewhat covalent..

THANK YOU -RIYA GUPTA X1 A1.