The marsh test was used historically to detect arsenic in cases of suspected poisoning. solid diarsenic trioxide and hydrogen gas react to form the gas forms arsenic trihydride and water. in order to create this reaction, 640 grams of diarsenic trioxide is reacted with 125 grams of hydrogen gas

The comparison of the number of atoms in a copper coin the size of a penny with the number of people on earth is made to illustrate which of the following? a. that atoms are indivisible b. that atoms are very small c. that atoms are very large d. that in a copper penny, there is one atom for every person on earth