Question

use your periodic table to predict the charges of the following ions:
be __ i ar na cl ca __
o __ k f s p mg __
se __ br he li n sr __
xe __ ba al kr h rb __

Explanation:

Step1: Group 2 (alkaline earth) ions

Group 2 elements lose 2 electrons:
$\text{Be}^{2+}$, $\text{Ca}^{2+}$, $\text{Ba}^{2+}$, $\text{Sr}^{2+}$, $\text{Mg}^{2+}$

Step2: Group 17 (halogen) ions

Group 17 elements gain 1 electron:
$\text{I}^-$, $\text{Cl}^-$, $\text{F}^-$, $\text{Br}^-$

Step3: Noble gas ions

Noble gases have no charge:
$\text{Ar}$, $\text{He}$, $\text{Xe}$, $\text{Kr}$

Step4: Group 1 (alkali) ions

Group 1 elements lose 1 electron:
$\text{Na}^+$, $\text{K}^+$, $\text{Li}^+$, $\text{Rb}^+$, $\text{H}^+$

Step5: Group 16 (chalcogen) ions

Group 16 elements gain 2 electrons:
$\text{O}^{2-}$, $\text{S}^{2-}$, $\text{Se}^{2-}$

Step6: Group 15 (pnictogen) ions

Group 15 elements gain 3 electrons:
$\text{P}^{3-}$, $\text{N}^{3-}$

Step7: Group 13 ion

Group 13 element loses 3 electrons:
$\text{Al}^{3+}$

Answer:

$\text{Be}^{2+}$, $\text{I}^-$, $\text{Ar}$, $\text{Na}^+$, $\text{Cl}^-$, $\text{Ca}^{2+}$
$\text{O}^{2-}$, $\text{K}^+$, $\text{F}^-$, $\text{S}^{2-}$, $\text{P}^{3-}$, $\text{Mg}^{2+}$
$\text{Se}^{2-}$, $\text{Br}^-$, $\text{He}$, $\text{Li}^+$, $\text{N}^{3-}$, $\text{Sr}^{2+}$
$\text{Xe}$, $\text{Ba}^{2+}$, $\text{Al}^{3+}$, $\text{Kr}$, $\text{H}^+$, $\text{Rb}^+$