Astudent takes four samples of a white crystalline solid and places each in a well plate. on top of each sample, she carefully places 20 drops of clear mystery liquids a, b, c and d. her results for each well are: liquid a: the solid dissolves quickly. liquid b: the solid appears unchanged. liquid c: the solid floats on top of the liquid. liquid d: fizzing occurs and the solid disappears. which combination of solid plus liquid indicates a chemical change has taken place?