Why was Dalton's atomic theory rejected or revised in the course of the development of the atomic theory
Answers
because of drawbacks ...his theory rejected .here listed some drawbacks.
Drawbacks of Dalton's Atomic Theory:
The atom is further subdivided into protons, neutrons and electrons.
The atoms of same elements are not similar in all respect. They may vary in mass and density. These are known as isotopes. For example: chlorine has two isotopes having mass numbers 35 a.m.u and 37 a.m.u.
Atoms of different elements are not different in all respects. Atoms of different elements that have the same atomic mass are called isobar.
According to Dalton atoms of different elements combine in simple whole number ratio to form compounds. This is not seen in complex organic compounds like sugar C12H22O11.
The theory fails to explain the existence of allotropes.
There are certain defaults in Dalton atomic theory-
1) he said that atoms are individual which can't be divided but other can be divided in e-mail,p+and n.
2)he said that atoms of same elements have same masses and chemical properties but for isotopes and isobars.