How do I know if a chemical equation is balanced? I have been explained this but I’m still quite confused. Here’s an example from my textbook:

e. g. H^2 + O^2 —> H^2O

How would you balance this? Please answer in as much detail as possible. Thanks!

2H2 + O2 —> 2H2O

Explanation:

H2 + O2 —> H2O

From the equation given above, there are 2 atoms of O on the left side and 1 atom of O on the right side. To balance O, put 2 in front of H2O as shown below

H2 + O2 —> 2H2O

Now we have a total of 4 atoms of H on the right side and 2 atoms of H on the left side. To balance this, put 2 in front of H2 as shown below:

2H2 + O2 —> 2H2O

Now we can see that the equation is balanced.

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.