Balance the following equation: underline ( )Mg+underline ( )HClarrow underline ( )MgCl_(2)+underline ( )H_(2)

To balance the chemical equation, we need to ensure that the number of atoms of each element is the same on both sides of the equation.<br /><br />Given equation: Mg + HCl → MgCl2 + H2<br /><br />Step 1: Count the number of atoms of each element on both sides of the equation.<br />On the left side:<br />- Mg: 1 atom<br />- H: 1 atom<br />- Cl: 1 atom<br /><br />On the right side:<br />- Mg: 1 atom<br />- H: 2 atoms<br />- Cl: 2 atoms<br /><br />Step 2: Balance the atoms by adjusting the coefficients.<br />To balance the chlorine atoms, we need to have 2 chlorine atoms on the left side. So, we need to multiply the coefficient of HCl by 2.<br /><br />Balanced equation: Mg + 2HCl → MgCl2 + H2<br /><br />Step 3: Verify the balanced equation.<br />On the left side:<br />- Mg: 1 atom<br />- H: 2 atoms<br />- Cl: 2 atoms<br /><br />On the right side:<br />- Mg: 1 atom<br />- H: 2 atoms<br />- Cl: 2 atoms<br /><br />The equation is now balanced.<br /><br />Answer: Mg + 2HCl → MgCl2 + H2