In the Ames Test, the appearance of his revertants in the presence of a non-mutagenic control compound indicates that .

Answer & Explanation:  The Ames test examines the mutagenic effects of chemicals ; as such, it detects whether a given chemical can cause a reversion mutation in his- bacteria. While this is the purpose of the test, some of the reversion mutations are not caused by the mutagen being tested  for. The appearance of his revertants in the presence of a non-mutagenic control compound therefore indicates that His+ revertants on the control plate are the result of spontaneous mutation.

explanation: it gains negative electrons, therefore becoming negatively charged. as charge cannot be created, nor destroyed, only transferred, this leaves the wool positive. now that they have opposite charges, the two items attract.

the answer for sodium is 0.186

the answer for rubidium is 0.251