Question

calcium ion; ca2+; ca2-; ca1+; ca1-

Explanation:

Calcium (Ca) typically loses 2 electrons to form a cation with a +2 charge, represented as $\text{Ca}^{2+}$. The other options ($\text{Ca}^{2-}$, $\text{Ca}^{1+}$, $\text{Ca}^{1-}$) do not represent the common charge state of a calcium ion.

Answer:

A. $\text{Ca}^{2+}$ (assuming the first option is labeled as A, with the text "Ca2+")