Question

question 3 of 10
which of the following elements is the least reactive metal?

a. chlorine (cl)

b. magnesium (mg)

c. sodium (na)

d. rubidium (rb)

Explanation:

1. First, identify the type of each element: Chlorine (Cl) is a non - metal. Magnesium (Mg), Sodium (Na), and Rubidium (Rb) are metals.
2. Then, recall the reactivity series of metals. Among metals, the reactivity generally increases as we go down a group and decreases as we move from left to right across a period in the periodic table. Sodium (Na) and Rubidium (Rb) are in Group 1 (alkali metals), and Rubidium is below Sodium in the group, so Rb is more reactive than Na. Magnesium (Mg) is in Group 2 (alkaline earth metals). Comparing the reactivity of Group 1 and Group 2 metals in the same period, Group 1 metals are more reactive than Group 2 metals. So among the given metals (Mg, Na, Rb), Magnesium is the least reactive.

Answer:

B. Magnesium (Mg)