Ionisation Energies Question|Chemistry Watch
So it's a table:
Question: Complete table 2 by suggesting a value for the third ionisation energy of Boron.
Ionisation energy/ KJ Mol-1 1st: 799 2nd: 2420 3rd: ? 4th: 25000 5th:32800
*If you could be as detailed as possible when answering that would be greatly appreciated. Thank you so much.
The third ionisation energy must be much lower than the fourth (due to: lower effective nuclear charge, electronic shielding, higher atomic radii and is less stable). However, it must also be higher than the the second ionisation energy (due to: greater effective nuclear charge yet the same atomic radii and electron shielding). Therefore, the third ionisation energy must be much lower than the fourth and slightly higher than the second. So I'd suggest the ionisation energy to be around 4800 KJ Mol-1.
Okay thank you, mark scheme says anywhere between 3500 and 10000 so you are correct.