In his atomic theory, Dalton proposed that all atoms of a given element are identical. Which of the following observations provides the best evidence that the proposal is incorrect?
A) The mass spectrum of Cu has a peak at 63amu and another peak at 65amu.
B) The ionic radius of Cl− is 0.181nm, and the atomic radius of Cl is 0.079nm.
C) The dipole moment of O3 is 0.53debye, and the dipole moment of O2 is 0.00debye.
D) Elemental P can exist in both white and red forms.
