11. Um elemento M apresenta os isótopos \( { }^{\mathrm{T}} \mathrm{M} \) e \( { }^{81} \mathrm{M} \). Sabendo que a massa atómica do elemento M é 79,90 determine os percentuais de cada isótopo de elemento M .

Balance the following chemical equation (if necessary): \( \mathrm{MnO}_{2}(\mathrm{~s})+\mathrm{HCl}(\mathrm{aq}) \rightarrow \mathrm{MnCl}_{2}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l})+\mathrm{Cl}_{2}(\mathrm{~g}) \)

Сила тока, которую необходимо поддержать для получения 16,2 г серебра путём электролиза раствора нитрата серебра за 30 минут, составляет__ А (выход по току 100 \( \%, F=96500 \mathrm{Kл} / \) моль)

How many oxygen atoms are located on the reactant side of the following chemical equation? \( \mathrm{C}_{3} \mathrm{H}_{8}(\mathrm{~g})+5 \mathrm{O}_{2}(\mathrm{~g}) \rightarrow 3 \mathrm{CO}_{2}(\mathrm{~g})+4 \mathrm{H}_{2} \mathrm{O}(\mathrm{g}) \)

Consider the reaction represented \( \mathrm{byCr}_{2} \mathrm{O}_{7}^{2-}+\mathrm{Cl}^{-} \xrightarrow{\text { i. Explain why the reaction is a redox reaction. }} \quad \mathrm{Cr}^{3+}+\mathrm{Cl}_{2} \) iii. Balance the redox equation State five physical properties of metals

\( 2 LiOH ( s ) \rightarrow Li 2 O ( s ) + H 2 O ( l ) \)