Question

what is s block elements ​

Answer 1

Elements that are present in group 1 and group 2 of the periodic table are called s - block elements.

Elements in group 1 are: Hydrogen, Lithium, Sodium, Potassium, Rubidium, Cesium, Francium. It's electronic configuration is ns1.

Elements in group 2 are: Beryllium, Magnesium, Calcium, Strontium, Barium, Radium. It's electronic configuration is ns2.

Answer 2

Answer:

Groups 1 and 2 of the periodic table in which the last electron enters the outermost s-orbital are called s-block elements.

Explanation:

s-orbital can accommodate only 2 electrons and that's why we have only groups 1 and 2 included in the s-block elements.

Group 1 consists of lithium, sodium, potassium, rubidium, caesium and francium. Group 1 elements are also called alkali metals. Its outermost electronic configuration is $ns^{1}$.

Group 2 consists of beryllium, magnesium,  calcium, strontium, barium and radium. Group 2 elements are also called alkaline earth metals. Its outermost electronic configuration is $ns^{2}$.