Reality Check
Penultimate Amazing
A "fudge factors like electron shielding" delusion
Adding obvious physics is not a fudge factor. We have a positive nucleus. We have inner negative elections in orbitals close to the nucleus. Obviously the inner electrons with their negative charge will partially shield the outer electrons from the positive nucleus
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Then there is the quantum mechanical (not possible classically) fact that full shells are more stable than partially full shells.
This is textbook chemistry.
Ionization Energy
29 November 2018 markie: A "fudge factors like electron shielding" delusion.Sure I do, and I know it uses fudge factors like electron shielding in order to better match experimental values.
Adding obvious physics is not a fudge factor. We have a positive nucleus. We have inner negative elections in orbitals close to the nucleus. Obviously the inner electrons with their negative charge will partially shield the outer electrons from the positive nucleus
!Then there is the quantum mechanical (not possible classically) fact that full shells are more stable than partially full shells.
This is textbook chemistry.
Ionization Energy
This effect, where the full positive charge of the nucleus is not felt by outer electrons due to the negative charges of inner electrons partially canceling out the positive charge, is called shielding. The more electrons shielding the outer electron shell from the nucleus, the less energy required to expel an electron from said atom. The higher the shielding effect the lower the ionization energy (see diagram 2). It is because of the shielding effect that the ionization energy decreases from top to bottom within a group. From this trend, Cesium is said to have the lowest ionization energy and Fluorine is said to have the highest ionization energy (with the exception of Helium and Neon).
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Electron orbitals are separated into various shells which have strong impacts on the ionization energies of the various electrons. For instance, let us look at aluminum. Aluminum is the first element of its period with electrons in the 3p shell. This makes the first ionization energy comparably low to the other elements in the same period, because it only has to get rid of one electron to make a stable 3s shell, the new valence electron shell. However, once you've moved past the first ionization energy into the second ionization energy, there is a large jump in the amount of energy required to expel another electron. This is because you now are trying to take an electron from a fairly stable and full 3s electron shell. Electron shells are also responsible for the shielding that was explained above.
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