Toxicity of Metal lons Zinc, copper, lead, and mercury ions are toxic to Atlantic salmon at concentrations of $6.42 \times 10^{-2} \mathrm{m} M, 7.16 \times 10^{-3} \mathrm{m} M, 0.965 \mathrm{m} M,$ and $5.00 \times 10^{-2} \mathrm{m} M,$ respectively. What are the corresponding concentrations in milligrams per liter?