Answer: Calcium is a reducing agent because it loses electrons and oxidises itself but reduces other reactants.
Explanation: Calcium belongs to the second group elements of the periodic table. All the elements present in group 2 have a +2 charge. Therefore the charge of calcium is Ca^{2+}. Calcium loses two electrons in a reaction and Ca is oxidized to Ca^{2+}. It acts as a reducing agent as it reduces it’s reactant and oxidises itself.