OBJECTIVES: 1. General Characteristics of s - Block elements and Their compounds
2. Importance of s- Block elements and their compounds in daily life
INTRODUCTION : 1. The s block elements are the those who receives valence electron in s sub shell. In periodic table elements belonging to group no. 1 and 2 are considered as s block elements.
2. The general electronic configuration of s block elements is lNoble gas ] ns1 and [ Noble gas ] ns2.
3.Gr. no. 1 consists of Li, Na, K, Rb , Cs and Fr. Gr. no. 2 consists of Be, Mg, Ca , Sr , Ba and Ra. Fr and Ra is radio active elements.
4. Elements belonging to group no 1 are collectively known as ALKALI METALS as they react with water and form hydroxides are strongly alkaline in nature.
5. Elements belonging to gr.no. 2 are collectively known as alkaline earth metals because their hydroxides and oxides are alkaline in nature and their metal oxide are found in earth crust.
6. Li and Be are the first members of alkali metal and alkaline earth metal . Both exhibit similar properties which are different from other element of respective groups and the resemblance in their properties is also known as DIAGONAL RELATIONSHIP. It is due to similarity in ionic size or charge/radius ratio of elements.
