Answer:
a. The student performed the splint test incorrectly. He should of observed a popping sound when the splint was placed in the test tube.
Explanation:
It is given that a student performed an experiment where he dropped a nickel metal in to HCl solution. He observed the reaction and performed a splint test in the test tube that is filled with a gas which is formed while Nickle is dropped into the solution of HCl.
But the experiment that the student performed was incorrect. He must have observed the popping sound when the splint was placed in the test tube.
When the splint was added to the gas splint flared up. The hydrogen gas pops out when exposed to the flame.

Thus the correct option is (a).
<span>The two techniques for separating an insoluble solid from a liquid are filtration and centrifuging. Filtration relies on the fact that the solid particles are smaller than the filter paper pores which allow the tiny molecules of liquid to pass through. With solids which dissolve in a liquid solvent, evaporation is commonly used to recover the solid and distillation is used to recover the solvent.</span>
Once it becomes balanced.
<span>The correct option is C. The concentration of phosphate inside the cytosol is already greater than the concentration of phosphate in the surrounding fluid, yet, the cell still want to move more phosphate into the cell. To do this, energy is needed to move the phosphate ions against the concentration gradient, so the type of transportation requires is ACTIVE TRANSPORT.</span><span />
The anwser is atoms are destroyed