Question

How does the chemical reactivity of alkali metals vary?

Answer 1

• The ability of an atom to lose or gain electrons in order to participate in any chemical reaction is termed as reactivity.
• Elements present in Group 1 of the periodic table, except for Hydrogen (H), are termed as alkali metals. It includes Lithium (Li), Sodium (Na), Potassium (K), Caesium (Cs), and Francium (Fr).
• On moving down the Group in alkali metals, the atomic size of atoms increases due to an increase in the number of shells. As the size of an atom increases, the ability of the metal to lose electrons increases and therefore, the reactivity of alkali metals increases down the Group.
• In Group 1, Lithium (Li) is present at the top of the Group followed by Sodium (Na), Potassium (K), Caesium (Cs), and Francium (Fr).
• Since the reactivity of alkali metals increases on moving down the Group, Francium is the most reactive alkali metal followed by Caesium, Potassium, Sodium, and Lithium.