Answer;
Barium
Explanation;
Group 2 metals get more reactive as we go down the group. The alkaline earth metals are the elements in Group 2 of the Periodic Table: beryllium, magnesium, calcium, strontium, barium, and radium. alkaline earth metals have low melting points and low densities for metals.
The decrease in reactivity down the group can be explained by the increase in ease at losing two outer electrons as we descend the group. The loss of electrons becomes easier due to the decreasing ionization energy required. Ionization energy decreases due to extra shielding from inner shells and increase in distance from the nucleus.
Answer: The correct answer is Barium.
Explanation: We are given some elements which belong to group 2 of the periodic table. These elements are considered as metals.
Reactivity of metals are defined as the ability of a metal to loose electrons easily.
In a periodic table, as we move down the group, the ability to loose the electrons increases and as a result, the reactivity of elements increases.
From the given elements, the last element which belongs to group 2 is Barium.
Hence, the most reactive element is Barium.
