I believe the scientist wants to test for the presence of carbonic acid in the solution. Bromthymol blue is a PH indicator and is mostly used in applications that require measuring substances that would have a relatively neutral pH. A common measure is for the measuring the presence of carbonic acid in a liquid. It may be used for observing photosynthetic activities, or as a respiratory indicator. As a carbon dioxide is absorbed from the breath into the solution, forming carbonic acid, the solution changes color from green to yellow.
The statement “force equals mass times acceleration” is Newton's second law of motion. It is a law rather than a theory because it states, rather than explains, the relationship between the variables.
Answer:Scientists have long believed that the 14 species of finches on the Galapagos Islands evolved from a single species of finch that migrated to the islands one to five million years ago (Lack, 1940).