Electrons 3 and 4 are also attracted by the nucleus. But negatively charged electrons repel one another. So, to avoid the electrons already in place, these electrons form a slightly larger sphere.
QM then says that electrons 5 and 6 organize into peculiar clouds with two lobes, one on either side of the nucleus.
The next two pairs (electrons 7 & 8, 9 & 10) form similar lobes. However, to avoid the earlier electrons, these lobes point in other directions.
