| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
| H | 1312 | |||||||
| He | 2372 | 5250 | ||||||
| Li | 520 | 7297 | 11810 | |||||
| Be | 899 | 1757 | 14845 | 21000 | ||||
| B | 800 | 2426 | 3659 | 25020 | 32820 | |||
| C | 1086 | 2352 | 4619 | 6221 | 37820 | 47260 | ||
| N | 1402 | 2855 | 4576 | 7473 | 9442 | 53250 | 64340 | |
| O | 1314 | 3388 | 5296 | 7467 | 10987 | 13320 | 71320 | 84070 |
| F | 1680 | 3375 | 6045 | 8408 | 11020 | 15160 | 17860 | 92010 |
| Ne | 2080 | 3963 | 6130 | 9361 | 12180 | 15240 | ||
| Na | 496 | 4563 | 6913 | 9541 | 13350 | 16600 | 20113 | 25666 |
| Mg | 737 | 1450 | 7731 | 10545 | 13627 | 17995 | 21700 | 25662 |
The teal colored cells represent ionization energies where the valence shell is now (n-1).
Why do you think there is such a large jump in the ionization energies when the n-1 shell is now valence?