Answer
Please see the work below.
Work Step by Step
The atoms with similar valence shell electronic configurations have similar chemical properties.
In the given atoms, (a) and (d) have 2 electrons in the valence shell and hence form a pair.
Atoms (b) and (f) have 5 electrons in the valence shell and show similar chemical properties.
Atoms (c) and (e) have 8 electrons in the valence shell and show similar chemical properties. They are inert gases.
