Which element is in the same group as Magnesium?

Which element is in the same group as Magnesium?

• A. Calcium
• B. Iron
• C. Sodium
• D. Aluminum

Answer: (A)

Elements in the same group on the periodic table have the same number of valence electrons, which leads to similar chemistry. Magnesium has two electrons in its outer shell (3s2). Calcium sits directly below magnesium in the same column (Group 2), so it also has two valence electrons (4s2). This shared outer-shell configuration means they commonly form similar ions (both form 2+ ions) and show comparable chemical behavior within the group. The other options belong to different groups: iron is a transition metal with a different electron structure, sodium is in Group 1 with one valence electron, and aluminum is in Group 13 with three valence electrons. So calcium is the element in the same group as magnesium.

Elements in the same group on the periodic table have the same number of valence electrons, which leads to similar chemistry. Magnesium has two electrons in its outer shell (3s2). Calcium sits directly below magnesium in the same column (Group 2), so it also has two valence electrons (4s2). This shared outer-shell configuration means they commonly form similar ions (both form 2+ ions) and show comparable chemical behavior within the group. The other options belong to different groups: iron is a transition metal with a different electron structure, sodium is in Group 1 with one valence electron, and aluminum is in Group 13 with three valence electrons. So calcium is the element in the same group as magnesium.