Many scientists think that this single event caused the extinction of most the dinosaurs which led to the rise of mammals which geologic principle is this an example of A. Geographism

B. Gradualism

C. Catastrophism

D. Uniformitarianism

C. Catastrophism

Explanation:

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

let that person have a turn to speak : )