Which parts of Daltons Atomic Theory are no longer believed to be true?
Dalton believed that all elements were composed of tiny indivisible particles called atoms. We now know that this is not true, there are particles found within the atom: protons, neutrons, & electrons. Dalton believed that all atoms of the same element were identical. We know this is not true. Isotopes are atoms of the same elemtn that have different mass numbers because of different numbers of neutrons, therefore, all atoms of the same element are NOT identical.