What are the major differences between the plum pudding and planetary models of the atom?

The plum pudding model of the atom didn't explain why the electrons weren't attracted to the protons they surrounded. It didn't have a nucleus depicting the nuclear force of the protons and neutrons in the atom (nuclear force allowed the nucleus to stay in one piece; not separate). The gold-foil experiment carried out by Rutherford and proved that an atom must have an inner part of great force (nucleus=nuclear force) did not support Rutherford's own plum pudding model, which didn't have a nucleus.

What are the major differences between the plum pudding and planetary models of the atom?
This is tough. We can't ethically give a homework answer. But I can try to point you toward one.





Why don't you try to look up Ernest Rutherford? I hope I've got the name right, it's been a while since I've studied this stuff.


That will tell you something about the plum pudding model.





And think a bit about the two; in the plum pudding model, the positively charged portion of the atom is spread out throug the total volume of the atom. In the planetary model it is compressed into a very small portion of the center. This has implications for those who are using atom smashers (particle accelerators).


In fact, it was such experiments that led physicists to understand the concept of the atomic nucleus at all.





Look that sort of stuff up and you're bound to come up with answers that will satisfy your teacher.