Which pair of elements would you expect to exhibit the greatest similarity in their physical and chemical properties?

Question

Quizplus · Accepted Answer

Ca and Sr are both in the same group (Group 2) of the periodic table, meaning they have the same number of valence electrons and similar physical and chemical properties. Cs and Ba are also in the same group but are less similar than Ca and Sr because Cs is more reactive and has a larger atomic radius than Ba. C and O are in different groups and have very different physical and chemical properties. Ga and Ge are in the same group but have slightly different physical and chemical properties due to their different number of valence electrons. H and Li are in different groups and have very different physical and chemical properties.

Which Pair of Elements Would You Expect to Exhibit the Greatest