Alkali earth metals occupy which column of the periodic table?

• A. Column 2
• B. Column 1
• C. Column 16
• D. Column 18

Answer: (A)

Alkali earth metals sit in the second column of the periodic table, i.e., group 2 (IIA). This placement comes from their two valence electrons in the outermost shell (ns2). Those two electrons give them a common tendency to lose two electrons and form a +2 ion, which is why they are grouped together with Be, Mg, Ca, Sr, Ba, and Ra. The other columns correspond to different valence electron counts—first column elements have one valence electron and form +1 ions (alkali metals), the column with six valence electrons corresponds to the chalcogens, and the far-right column contains the noble gases with full valence shells and high inertness.