why is there such a large jump in ionization energy between the second andthird ionizationenergiesformagnesium

Answer 1

Magnesium has 2 valence electrons. Hence, the first and second ionization energies are not as much as third ionization energy. Its already difficult to remove its third electron because it would come from an orbital that follows the octet rule (meaning already stable). To visualize:

1st ionization: Mg + energy ---> Mg+ + e-
2nd ionization: Mg+ + energy ---> Mg2+ + e-
note that Mg2+ is the stable form of magnesium ion, it occurs naturally.
3rd ionization: Mg2+ + energy ---> Mg3+ + e-
note that Mg3+ does not occur naturally

Answer 2

Take a look at the electron configuration of Mg. [Ne]3s^2 or if you prefer 1s^2 2s^2 2p^6 3s^2 This tells you the number of electrons in the various energy levels. the first ionization energy is needed to remove the first electron from the 3s-orbital (the 3rd energy level) If you are not familiar with orbitals or enrgy levels think at them as "shells". Mg(g) ---> Mg^+ (g) + e^- The second ionization energy is needed to remove the 2nd electron from the 3s-orbital. Mg^+(g) ---> Mg^2+ (g) + e^- The 2nd energy is higher, because the nucleus has a positive charge +1 and this will increase the attraction forces between the nucleus and the electron. the 3rd ionization energy increases significantly as you have noticed. Why? because - the 3rd electron is in the 2s-orbital. It has a lower energy than the 3s-orbital, but it is closer to the nucleus, which has now a charge of +2. The attraction is therefore higher. - The "shielding" effect has been reduced. Between the 3rd electron and the nucleus are only the 1s^2 electrons. The noticable increase of 3rd. ionization energy is a typical pattern for a break in to lower energy levels!

Answer 3

Magnesium has two valence electrons in the 2s orbital. When you remove the 2s electrons you get a Helium-like electron configuration with a 1s core. So it is difficult to achieve the correct terms you had wanted by taking away the third ionization energy, hence the "jump".

Answer 4

There are more electrons look at the formula for the shell and the number of electrons(protons) you realize it is not simply linear.
get a good fundamental inorganic chem book
egs are Chemistry in action for the states
I prefer british authored books personally