Question

what is daltons atomic theory and what two parts have been changed today?

Answer 1

Here are the key ideas of Dalton's theory:

1. All matter is composed of atoms
2. Atoms cannot be made or destroyed
3. All atoms of the same element are identical
4. Different elements have different types of atoms
5. Chemical reactions occur when atoms are rearranged
6. Compounds are formed from atoms of the constituent elements.

We know that (at least) 2. and 3. are wrong because
2. We can destroy atoms and create them. We do so in nuclear fusion and fission. The sun is doing it right now, destroying hydrogen atoms to create helium atoms
3. There are isotopes of the same element. (What's an isotope? Look it up!!!)

Answer 2

dalton said that atom is the smallest undivisible particle, though this is wrong in whole, because niether the atom is smallest and also it can be divided into sub particles and evn those particles can be now divided further so this aspect of his theory is wrong