Mrs. Johnston heated 5 grams of sugar. The sugar first looked shiny, and then it melted and became dark brown. Finally, all that was left was a black, shiny residue. She then heated 5 grams of sand in the same way. The sand’s appearance did not change. What explains these results? a Sand is an element, but sugar is a compound.
b Heating the sugar caused a chemical change.
c Heating the sand caused a chemical change.
dHeat only caused physical changes in both the sand and sugar.