The numbers of electrons, their configuration, for the given species are:
| Species |
No. of electrons |
Configuration |
Nb |
Na |
Bond order |
| H2+ |
1 |
(δ1S)1 |
1 |
0 |
0.5 |
| H2 |
2 |
(δ1S)2 |
2 |
0 |
1 |
| He2 |
4 |
(δ1S)2(δ *1S)2 |
2 |
2 |
0 |
The bond length in H2+ is longer than in H2 because only one electron is present to shield the two nuclei from mutual repulsion. In H2,there are two electrons to hold the two nuclei ,thus nuclear repulsion is less than that in H+2. Hence, nuclear separation in H+2 is more than in H2 .
