Answer:
Both are unreactive.
Explanation:
Atom Number of Electrons
A 2
D 10
The two atoms A and D are very stable and unreactive.
Valence electrons the outermost shell electrons in a neutral atom.
The number of valence electrons in A is 2
The number of valence electrons in D is 8
The atoms are stable and unreactive because for A, its two electrons are in the k-shell in which the maximum number of electrons here is 2. It has a noble configuration which makes it stable.
For atom D, the outermost electrons are in the L-shell in which the maximum number of electrons is 8. This also makes it stable and unreactive.
Both atoms will be reluctant to lose or gain electrons.
