When substances go through chemical changes, which of the following will always happen? A. Exactly one new substance will form and one will be destroyed. B. One or more substances will be completely destroyed. C. A gas will form or a white solid will precipitate. D. One or more substances with different chemical properties will form.

I would say D. When any substance undergoes a chemical change, it can't be said for certain that any of them will be destroyed (I don't think the word destroyed really encompasses it, reactants aren't destroyed they just change chemically to form the product). And the exact number of new substances that we will be formed depends on the reaction, for example a double replacement reaction would create two new substances, meanwhile a single replacement would only create one. You do know for certain, since you know it's a chemical change, that some substance with a different chemical property than the reactants will form. So, One or more substances with different chemical properties will form.

The answer D. One or more substances with different chemical properties will form. Explanation: During a chemical change, two or more substances react to form one or more products. The reaction produces one or more new substances. Since the new substances have different identities than the reactants, the chemical properties are different. Therefore, when substances go through chemical changes, one or more substances with different chemical properties will always form. Some, but not all, chemical changes result in the formation of a gas or the precipitation of a white solid. Also, matter changes forms, but it can never be destroyed.