Question

Which is a sign of a chemical change? A) Ice cream left at room temperature melts. B) Calcium chloride is dissolved in H2O and disappears. C) Paint on a freshly painted wall dries and is no longer sticky. D) When H2S gas is bubbled into a lead acetate solution, a precipitate forms.

Answer 1

D, because a physical change is when something changes but doesn't change into a new substance. A chemical change is when something changes into a new substance.

Answer 2

Chemical change is any change that results in the formation of new chemical substances. (Thanks to google)

This the answer is D