Earlier the following points were proposed for an atom that:
A. Elements are different kinds of atoms. : For example atom of oxygen will be different from atom of carbon.
B. All matter is made up of atoms: it is also true that whatever matter we observe is made up of some atom. Either it is a mixture or pure substance.
C. Atoms cannot be divided: This is not true. Further scientific studies showed that an atom can further be divided into sub atomic particles electrons, neutrons and protons. Thus the idea of indivisibility of an atom changed when new evidence was discovered.
D. Atoms are made up of smaller particles: It is true as atoms are made up of sub atomic particles.
