Consider isotopes ions protons and electrons. how many of these did dalton not discuss in his atomic theory?

Answer: He did not discuss about any of these.

Explanation: Dalton proposed some of the postulates for his atomic theory. They are:

1) Matter is made up of atoms which are not divisible.

2) Atoms of different elements combine in a fixed ratio to form compounds.

3) The atomic properties of given element are same including mass. This states that all the atoms of an element have same mass but the atoms of different elements have different masses.

4) No atoms are either created or destroyed during a chemical reaction.

5) Atoms of an element are identical in mass, size and other chemical and physical properties.

As it is visible from the postulates, he only discussed only about the atoms but not subatomic particles or isotopes.