| element | 1st IE/kJmol-1 | 2nd IE/kJmol-1 | 3rd IE/kJmol-1 |
| Li | 519 | 7300 | 11800 |
| Na | 494 | 4560 | 6940 |
| K | 418 | 3070 | 4600 |
| Rb | 402 | 2650 | 3850 |
| Cs | 376 | 2420 | -------- |
| Be | 900 | 1760 | 14800 |
| Mg | 736 | 1450 | 7740 |
| Ca | 590 | 1150 | 4940 |
| Sr | 548 | 1060 | 4120 |
| Ba | 502 | 966 | 3390 |
1. Describe the trend in the first ionisation energy of group
one.
2. Explain the trend in the first ionisation energy of group one.
3. Describe the trend in the first ionisation energy of group two.
4. Explain the trend in the first ionisation energy of group one.
5. Describe the difference between any adjacent pair of values in the table
above and explain the difference.