Question

Which of dalton's postulates about atoms are inconsistent with later observations? do these inconsistencies mean that dalton was wrong? is dalton's model still useful? explain?

Answer 1

1)  Dalton stated that atom is matter that can not be divided, but it is proved that the atom can be divided into subatomic particles  (electrons, protons and neutrons).

2) He stated that atoms of one element can not be changed into atoms of other  elements, but now that is possible by nuclear reactions.

Today we still use his postulate: Atoms combine in the ratio of small whole numbers to form stable compounds, for example H₂O.