Which statement is true about chemical reactions?

• A. They represent the way matter is created and destroyed.
• B. They reach chemical equilibrium when the amounts of products and reactants are equal.
• C. They may have different numbers of a given atom on each side of the equation arrow.
• D. They involve the making and breaking of chemical bonds.

Answer: (D)

Verified step by step guidance

1. Understand that chemical reactions involve the transformation of substances through the making and breaking of chemical bonds.
2. Recognize that in a chemical reaction, atoms are rearranged, but matter is neither created nor destroyed, adhering to the law of conservation of mass.
3. Identify that chemical equilibrium in a reaction is reached when the rate of the forward reaction equals the rate of the reverse reaction, not necessarily when the amounts of products and reactants are equal.
4. Acknowledge that a balanced chemical equation must have the same number of each type of atom on both sides of the equation arrow, reflecting the conservation of mass.
5. Conclude that the true statement about chemical reactions is that they involve the making and breaking of chemical bonds, which is fundamental to the process of chemical change.