Not really.
They can be 'designed' to elicit a certain reaction in an audience, but, if the audience is aware of how film-makers manipulate them, then they can avoid reacting predictably.
Indicators are compounds that react with acids and bases to make certain colors. (:
Yes
They study chemicals and see how they react to certain situations.=
Certain gases that react with oxygen, for example hydrogen.
no
Concentration
Cat videos can help people understand their behavior by scientifically recording how cats react to certain impulses and situations. Most cat videos, however, or recorded of cat behavior at its furthest extremes. Therefore, most cats will not behave the same way as most cat videos.
They watch them in certain studies. They might also provide surveys to see how people would react to certain things.
Blood types do not determine your personality. Your upbringing and other genes in you body determine how you react to certain situations and how your personality is.
That depends which chemicals you are using, certain chemicals react a lot faster or heavier than others.
Yes, most notably acids will react with bases and some metals.
Most elements will react with at least one other substance. Certain groups of elements have certain substances that they react or don't react with. For Example, Group 1 - Alkali Metals all react vigourously with water. The Inert Gases (exc. Radon) are all highly unreactive and react with a very small amount of substances, if any.