Astudent is investigating the affect of different salts on melting points. four patches of ice of equal size are roped off and a different type of salt is poured on each, one receives table salt (nacl), one receives calcium chloride (cacl2), one receives potassium carbonate (kco3) and the fourth receives inert sand instead. each patch receives an equal amount of salt or sand. the student measures the volume of ice remaining and subtracts it from the original volume of ice to see how much melted away. what is a control variable in this experiment?

The inert sand

Explanation:

A control variable is the variable in which the experiment does not depend on. The outcome of the control variable does not in any way validate or invalidate an experimental procedure.

The student seeks to investigate the effect of different salts on melting point. He used NaCl, CaCl₂, K₂CO₃ and inert sand. The first three are salts. Sand is made up of silica, SiO₂ and it is not a salt. Therefore, the control variable here is the inert sand. Sand is highly unreactive and would not in any significant way help the investigation.

the answer is option a.

c. orbital shape i hope this is correct