$\overset{+1}{\mathop{H}}\,\overset{X}{\mathop{Cl}}\,\,:\,\,1\left( +1 \right)+X=0\Rightarrow \,\,X=-1$

$\overset{+1}{\mathop{H}}\,\overset{X}{\mathop{Cl}}\,{{\overset{-2}{\mathop{O}}\,}_{4}}\,:\,\,1\left( +1 \right)+X+4\left( -2 \right)=0\Rightarrow \,\,X=+7$

$\overset{+1}{\mathop{I}}\,\overset{X}{\mathop{Cl}}\,\,:\,\,1\left( +1 \right)+X=0\Rightarrow \,\,X=-1$

${{\overset{X}{\mathop{Cl}}\,}_{2}}\overset{-2}{\mathop{O}}\,:\,\,\,\,2\left( X \right)+1\left( -2 \right)\,\,=0\,\,\,\,\,\,\Rightarrow \,\,\,X=+1$