Calcium and magnesium belong to which group on the periodic table?

• A. Alkali metals
• B. Metalloids
• C. Alkaline earth metals
• D. Halogens

Answer: (C)

Calcium and magnesium are both classified as alkaline earth metals, which are found in Group 2 of the periodic table. This group consists of elements characterized by having two electrons in their outermost shell, which they tend to lose easily during chemical reactions, resulting in a +2 oxidation state. This property is indicative of their reactivity and contributes to their common occurrence in compounds.

The alkaline earth metals are known for forming various compounds, particularly oxides and hydroxides, that exhibit basic properties when dissolved in water. As you move down the group, the reactivity increases, which is evident when comparing magnesium and calcium with barium and radium.

The other groups mentioned do not contain calcium and magnesium. Alkali metals are in Group 1 and have one electron in their outer shell, while metalloids possess properties intermediate between metals and non-metals, and halogens are in Group 17, characterized by highly reactive non-metals. Therefore, the classification of calcium and magnesium as alkaline earth metals is accurate based on their group characteristics and chemical behavior.