Question

Describe at least two experiments, including the observed results, that caused the scientific community to accept changes to Dalton’s original model of the atom.

Answer 1

Avogadro's Law and the fact that you need 2 volumes of hydrogen per 1 volume of oxygen to make water suggested some compounds were made of more than one of a given type of atom, in this case H2O, not HO.

Answer 2

thank you

Answer 3

more importantly, the gold foil expt, and the oil drop expt

Answer 4

J, you are thinking, perhaps, of experiments that proved that the atom was not indivisible, which Dalton assumed? I would argue the better experiments are those of Thomson, which showed that electrons could be torn from atoms -- and therefore that the atom was made of still smaller parts.

In its context, the Geiger-Marsden experiment just demonstrated one structure for the atom versus another -- but Dalton had not proposed any structure at all for the atom, because he had no idea that it was composed of anything smaller. Millikan's experiment was focussed on the mass of the electron, and said nothing per se about the atom.

Answer 5

@Carl_Pham, yes, thomson's experiment is a better fit than the oil drop, however I still believe it answers the question of "changes to Dalton's original model" better than avogadro's law, which changes Dalton's laws of proportions, but doesn't change the model of the atom to do so.

Answer 6

You're right, J. I had forgotten that Dalton knew about multiple proportions.