Question

Which (if any) of Dalton's 5 Atomic Theory postulates were proved wrong by Thomson and/or Rutherford? If one was proved wrong, what did Thomson and/or Rutherford discover to prove it wrong?

Answer 1

J.J. Thomson and Ernest Rutherford disproved different postulates of Dalton's Atomic Theory.

Step-by-step explanation:

In Dalton's Atomic Theory, there are five postulates:

1. Atoms are indivisible and indestructible.
2. All atoms of a given element are identical in mass and properties.
3. Compounds are formed by a combination of two or more different kinds of atoms.
4. A chemical reaction is a rearrangement of atoms.
5. Atoms are neither created nor destroyed in a chemical reaction.

J.J. Thomson's experiments with the cathode ray tube discovered the electron, disproving Dalton's first postulate. He demonstrated that atoms are divisible and made up of subatomic particles.

Ernest Rutherford's gold foil experiment provided evidence for the existence of an atomic nucleus, disproving Dalton's second postulate. He discovered that the positive charge and most of the mass of an atom are concentrated in a small, dense nucleus.