Question

An experiment measures the growth of crystals in a liquid solution aboard the space shuttle. A collection of bottles has the liquid in varying strength, or concentration of the tested substance. What would be a control observation in this experiment?
A. the bottle with 0% concentration


B. the bottle with the weakest concentration


C. the bottle with the strongest concentration


D. the bottle with the medium amount of concentration

Answer 1

The correct answer is option A, that is, the bottle with zero percent concentration.  

The control in the given case would have the liquid in it in the absence of any supplemented dissolved solute. So, as to find whether the solution is making the crystal formation or the liquid can do it by itself.  

The control refers to one element, which is not changed at all through the experiment, as its unchanging condition permits the association between the other variables being examined to be better comprehended.