Operant conditioning, sometimes called <em>instrumental learning</em>, was first extensively studied by Edward L. Thorndike, who observed the behavior of cats trying to escape from home-made puzzle boxes.
Hope this helps!
I only know about the Water tank which is the most accurate. You place your body in it, and weights are added I think. Somehow some measurements are gathered to get your body fat weight. Online calculators exist, as well as electronic waves that are sent int your body, the echo is recorded and analyzed.
If you take a fluid (i.e. air or water) and heat it, the portion that is heated usually expands. The same mass takes up more volume and as a consequence the heated portion becomes less dense than the portion that is<span><span> not heated.</span> </span>
A compound is a substance that consists of two or more elements, which is chemically combined, meaning that it could only be split by chemical means.
Examples:-
- NaCl is salt, chemically combined of Sodium and Chloride.
- H2O is water, chemically combined of Hydrogen and oxygen.
I believe the answer is A