Question

Which of these changes produces a chemical change?

A. A stone fizzes and forms a gas when ácid is dropped on it.

B. Lava cools and changes from a thick fluid to solid rock.

C. A large rock is crushed into gravel.

D. Limestone slowly dissolves in water and forms a cave.​

Answer 1

A

Step-by-step explanation:

Fizzing is and forming a gas is a chemical reaction whereas the rest are simply changing physically. Lava's composition is not changed when turning to rock. A rock being crushed is not changing chemically, only physically. Limestone continues to be limestone after dissolving in water and only physically changes forms into a cave. Also emitting gas is a key aspect of chemical reactions