An example of an alternative conception:
"Hydrogen has just one electron, close to the nucleus. Helium has two electrons, each at the same distance from the nucleus. Lithium has three electrons, the first two at the same distance from the nucleus as the helium electrons (in the same 'electron shell', in the jargon of quantum theory), with the third slightly further out from the nucleus. … Without the exclusion principle, all atoms would collapse to the size of a hydrogen atom…"
John Gribbin (1996) Companion to the Cosmos. (Ed., Mary Gribbin) Weidenfeld & Nicolson.
This alternative conception (which ignores the different positive charge on different atomic nuclei) is commonly found among learners, and is here repeated in a science reference book.
Read about the nature of alternative conceptions
Read about some examples of science misconceptions
Read about historical scientific conceptions
