What is the name of the cation in each of the following compounds?

$C a O$ $N {a}_{2} S {O}_{4}$ $K C I {O}_{4}$ $F e {\left(N {O}_{3}\right)}_{2}$ $C r {\left(O H\right)}_{3}$

$\text{Calcium, sodium, potassium, iron, and chromium ions.}$
The actual cations are $C {a}^{2 +}$, $N {a}^{+}$, ${K}^{+}$, $F {e}^{2 +}$, and $C {r}^{3 +}$. An ionic material forms when the charges of anion and cations are balanced. All of I have done here is to balance the charges. $C l {O}_{4}^{-}$, $N {O}_{3}^{-}$, and $S {O}_{4}^{2 -}$ are ions you will learn to recognize.