How does an oxide ion, fluoride ion & a neon atom have the same electron configuration but different charges?
The electron configuration for all of then is the same, but the number of protons in the middle of the atom are different. The charge is the number of protons minus the number of electrons. For example, oxide is based on oxygen. Oxygen and oxide have 8 protons. However, 10 electrons are present in oxide, so it has a charge of -2. On the other hand, neon has 10 protons, and 10 electrons are present. The final charge is 0. The magnesium ion has 12 protons, but 10 electrons. +2 charge. The sodium ion has 11 protons, but 10 electrons. +1 charge. The flouride ion has 9 protons, but 10 electrons. -1 charge. The way it works is that electrons like to fill entire spheres. The first sphere that electrons fill can hold up to 2 electrons. The second sphere that electrons fill can hold up to 8 electrons. To have a “full” second sphere, elements like oxygen form oxide ions and pick up 2 extra electrons.
