EVERYDAY SCIENCE

Detailed explanation-1: -The alkali metal electron configurations (group 1) always end with “s1” and the alkaline earth metals (group 2) always end with “s2”. These 2 groups are know as “s block” elements.

Detailed explanation-2: -Reactivity of Group 1 Elements The reactivity of alkali metals increases from the top to the bottom of the group, so lithium (Li) is the least reactive alkali metal and francium (Fr) is the most reactive. Because alkali metals are so reactive, they are found in nature only in combination with other elements.

Detailed explanation-3: -The reactivity of Group 1 elements increases as you go down the group because: the atoms get larger. the outer electron gets further from the nucleus. the attraction between the nucleus and outer electron gets weaker – so the electron is more easily lost.

Detailed explanation-4: -As the metallic nature of the alkali metals increases from Lithium to caesium, the ionic nature of the corresponding hydrides also increases from LiH to CsH. The thermal stability of the alkali metal hydrides decreases from lithium hydride to Caesium hydride as the metallic nature increases from Lithium to caesium.