Which balances the equation Mg+O_(2)arrow MgO Mg+2O_(2)arrow 4MgO 2Mg+2O_(2)arrow 2MgO 2Mg+O_(2)-2MgO 2Mg+2O_(2)-4MgO

To balance the chemical equation \( \text{Mg} + \text{O}_2 \rightarrow \text{MgO} \), we need to ensure that the number of atoms of each element is the same on both sides of the equation.<br /><br />1. **Identify the elements involved**: Magnesium (Mg) and Oxygen (O).<br /><br />2. **Count the atoms on each side**:<br /> - On the left, we have 1 Mg atom and 2 O atoms (from \( \text{O}_2 \)).<br /> - On the right, in \( \text{MgO} \), we have 1 Mg atom and 1 O atom.<br /><br />3. **Balance the magnesium atoms**: We already have 1 Mg on both sides, so they are balanced.<br /><br />4. **Balance the oxygen atoms**: We have 2 O atoms on the left and only 1 O atom on the right. To balance the oxygen, we need 2 MgO molecules on the right side because each MgO contains 1 O atom. This gives us 2 O atoms on the right side.<br /><br />5. **Adjust the magnesium atoms accordingly**: Since we now have 2 MgO molecules on the right, we need 2 Mg atoms on the left to balance the magnesium.<br /><br />The balanced equation is:<br /><br />\[ 2\text{Mg} + \text{O}_2 \rightarrow 2\text{MgO} \]<br /><br />Therefore, the correct option is:<br /><br />\[ 2\text{Mg} + \text{O}_2 \rightarrow 2\text{MgO} \]