Balancing a chemical equation means ensuring that the number of atoms of each element is the same on both sides of the equation. To balance an equation, we can change the coefficients in front of the compounds. Here are some steps on how to balance a chemical equation:

1. Count the number of atoms of each element on both sides of the equation.

2. Start by balancing the element that appears in only one compound on each side. To do this, adjust the coefficients in front of the compounds that contain that element until the number of atoms is the same on both sides.

3. Next, balance the element that appears in two or more compounds on one side of the equation. Adjust the coefficients in front of the compounds that contain that element until the number of atoms is the same on both sides.

4. Repeat steps 2 and 3 until all elements are balanced.

5. If necessary, simplify the equation by dividing all coefficients by a common factor.

Here's an example of how to balance the equation for the combustion of methane:

CH4 + 2O2 -> CO2 + 2H2O

Initially, there are 1 carbon atom, 4 hydrogen atoms, and 2 oxygen atoms on the left side of the equation. On the right side, there are 1 carbon atom, 2 oxygen atoms, and 4 hydrogen atoms.

To balance the carbon atoms, we put a coefficient of 1 in front of CO2:

CH4 + 2O2 -> 1CO2 + 2H2O

Now, there is 1 carbon atom on both sides of the equation.

Next, we balance the hydrogen atoms by putting a coefficient of 2 in front of H2O:

CH4 + 2O2 -> 1CO2 + 2H2O

Now, there are 4 hydrogen atoms on both sides of the equation.

Finally, we check the oxygen atoms and see that they are already balanced with 2 oxygen atoms on both sides.

To simplify the equation, we can divide all coefficients by 1:

CH4 + 2O2 -> CO2 + 2H2O

The resulting equation is balanced with 1 carbon atom, 4 hydrogen atoms, and 2 oxygen atoms on both sides.