Answer: emission spectrum
Explanation:
15.999 is the mass of oxygen
Answer : B) In step 2, there was a chemical change which was observed in sugar.
Explanation : In A step 2 there was a physical change that was seen. By just boiling the dissolved salt solution salt was obtained. Therefore, it is a physical change. In B step 2 there was a chemical change seen as sugar solution was thickened and turned brown. It was not obtained in its original form; there was a chemical reaction that took place during sugar evaporation. As chemical change is the one where the reaction is irreversible.
Therefore only in B step 2 there was a chemical change that was observed.
The correct answer is D, the Endothermic Process.
Hope I helped. :)