Which situation provides the best evidence that a chemical reaction is taking place?

When a comet collides with earth, it adds material to our planet and causes great damage. therefore, a collision like this is a a. destructive force b. constructive force c. geologic process and event d. constructive and destructive force

You may expect bonds between two atoms which each have n covalent lonic metallic hydrogen

Melissa is interested in her family tree and how her family has changed over its many generations. melissa probably more closely resembles