There is the same overall number of atoms of each element on the reactants side as on the products side, they are simply rearranged. Also, mass is conserved as atoms cannot be created or destroyed by a chemical reaction.
What goes in, must come out. So the elements on the right hand side, are also on the left hand side. Just bonded differently
The elements on the reactant and product sides of a chemical equation must have the same number of atoms for each element due to the law of conservation of mass. This means that while the total atoms are conserved, they can be rearranged into different molecules. Balancing chemical equations ensures that this conservation holds true.
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