Question

The least reactive element in group 1-A is .

Answer 1

About Group 1 (A) :

In the modern periodic table(or long form of periodic table), the group 1-A elements( alkali metals) are Lithium(Li) ,Sodium(Na), Potassium (K), Rubidium(Rb) and Cesium (Cs).

Reactivity Trend:

• Down the group, the chemical reactivity of the elements increases.
• Chemical reactivity can be defined as the tendency of losing electrons. Down the group atomic size increases and thus, the tendency to lose electrons increases. Therefore, the chemical reactivity increases down the group.
• Thus, Lithium being the first element in the 1-A group has the least reactivity.

Hence, The least reactive element in group 1-A is Lithium(Li).