Which of the following is an unbalanced equation? CaCO_(3)arrow CaO+CO_(2) CS_(2)+underline (2)O_(2)-gt CO_(2)+underline (2)SO_(2) 2Na+2H_(2)Oarrow 2NaOH+H_(2) PbO_(2)+2H_(2)-gt 2Pb+H_(2)O

The correct answer is: $CS_{2}+2O_{2}\rightarrow CO_{2}+2SO_{2}$<br /><br />Explanation:<br />An unbalanced chemical equation is one in which the number of atoms of each element is not the same on both sides of the equation. In the given options, the equation $CS_{2}+2O_{2}\rightarrow CO_{2}+2SO_{2}$ is unbalanced because the number of sulfur atoms is not the same on both sides of the equation.