What you meant must be the adaptive advantage of the frogs' lungs. Frogs are considered as amphibians wherein the have this unique ability to reside either on land or in water. Their specialised lungs could be responsible to these which makes them capable of breathing oxygen in water and land.
Answer:
I think I it is selective breeding also known as artificial selection
<span>We know that electrons are occupied on a cloud surrounding
the nucleus. So which means that the bigger the electron cloud, the bigger the
number of electrons. So in this case, since Na shrank so it lost some
electrons. And since Cl+ grew in size of the electron cloud so electron was
added to it.</span>
