The true statement about chemical reactions is:
They involve the making and breaking of chemical bonds.
The other statements are false for the following reasons:
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They reach chemical equilibrium when the amounts of products and reactants are equal. This is incorrect; chemical equilibrium is reached when the rates of the forward and reverse reactions are equal, not necessarily when the amounts of products and reactants are equal.
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They may have different numbers of a given atom on each side of the equation arrow. This is false; in a properly balanced chemical equation, the number of each type of atom must be the same on both sides of the equation to obey the law of conservation of mass.
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Only inorganic molecules can participate in chemical reactions. This is inaccurate; both organic and inorganic molecules can participate in chemical reactions.
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They represent the way matter is created and destroyed. This statement is false; chemical reactions do not create or destroy matter but rather rearrange atoms from reactants to products, following the law of conservation of mass.