One of the Main Features of Dalton's Atomic Theory No

Multiple Choice

One of the main features of Dalton's atomic theory no longer considered valid is: All atoms of each element are identical in every respect.Which of the following is the best explanation of why this feature is no longer considered valid?

A) The existence of isotopes
B) Mass is conserved in a chemical change
C) Nearly all of the mass of an atom is concentrated in the nucleus
D) The total charge of the electrons of an atom exactly balances the positive charge of the nucleus
E) The planetary model of the atom has been shown to be incorrect