# Question #eec3c

Oct 28, 2015

$\textcolor{red}{\text{For ionic bonds}}$: knowing the oxidation states of the elements

$\textcolor{red}{\text{For covalent bonds}}$: knowing how many electrons are in the valence shell

#### Explanation:

There really are no shortcuts for this one. You need to practice writing chemical equations by answering practice tests.

metal: $B {e}^{\text{2+}}$ ; non-metal: $C {l}^{-}$ $\rightarrow$ $B {e}_{1} C {l}_{2}$, or simply $B e C {l}_{2}$
metal: $A {l}^{\text{3+}}$ ; non-metal: $O {H}^{-}$ $\rightarrow$ $A l {\left(O H\right)}_{3}$
metal: $C {u}^{\text{3+}}$ ; non-metal: $S {O}_{4}^{\text{2-}}$ $\rightarrow$ $C {u}_{2} {\left(S {O}_{4}\right)}_{3}$