Creating new elements in order to study their properties is definitely pure research.
It has no earthly [known] application, since the elements don't even exist, whereas
for each of the other choices, you've stated the desired application as the reason
for the search.
Liquids<span> are not </span>packed<span> as tightly as </span>solids<span>. And gases are very loosely </span>packed<span>. The spacing of the molecules enables </span>sound<span> to travel much faster through a </span>solid<span> than a gas. </span>Sound<span> travels about four times faster and farther in water than it does in air.</span>
Evaporation (or another word to use is water vapor.)
Answer:
v=32.9m/s
Explanation:
The acceleration needed to mantain a circular motion of radius r and speed v is given by the equation 
This is the centripetal acceleration. The person will feel what is called a centrifugal acceleration, of the same value, because he is not in an inertial frame (thus subject to fictitious forces, product of inertia).
We want to know the speed of his head when it is subject to 12.5 times the value of the acceleration of gravity while moving on a 8.84m radius circle, so we must do:

A.
They’re supposed to help the person and cannot diagnose them as that is the job of a doctor