Identify the type of chemical reaction. h2co3 h2o + co2 decomposition exchange reversible synthesis

25) a student 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: a brownish colored liquid is produced. liquid d: fizzing occurs and the well becomes warmer. in which well does a physical change occur?

Which entry is in the wrong position in the table?

All vaccination should(n’t) be mandatory! 1.at least 5 sentences explaining 2.why? 3.in the end summarize the sentence