calculate: samples A, B, and C have masses of 80 grams, 12 grams, and 33 grams and volumes of 20 milliliters, 4 milliliters, and 11 milliliters respectively. Which of the samples have the same density?

The characteristics of two different types of reactions are shown below: reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of an element. which statement is true about the atoms of the elements that participate in the two reactions? their identity changes in both reaction a and reaction b. their identity changes in reaction a but not in reaction b. their identity changes in reaction b but not in reaction a. their identity remains the same in both reaction a and reaction b.