Question

1. according to the law of conservation of mass, *

a. matter is always created in a chemical reaction
b. matter is always destroyed in a chemical reaction
c. matter is created and then destroyed in a chemical reaction
d. matter is not created or destroyed in a chemical reaction

1. in making a pizza, which process involves a chemical change? *

a. mixing spices for the sauce
b. slicing pepperoni for the topping
c. spreading cheese on the pizza
d. baking the dough to form the crust

Explanation:

• For Question 13: The Law of Conservation of Mass states that in a chemical reaction, matter is neither created nor destroyed. It just changes form.
• For Question 7: A chemical change results in the formation of new substances. Baking dough involves chemical reactions (like yeast fermentation producing carbon dioxide, and heat causing chemical changes in the dough's components) to form a new substance (the crust). Mixing spices (A), slicing pepperoni (B), and spreading cheese (C) are physical changes as no new substances are formed.

Answer:

1. D. matter is not created or destroyed in a chemical reaction
2. D. baking the dough to form the crust